Program
 
Mon Oct 03 2022
08:15 - 09:45
Registration
09:45 - 09:50
nanoGe Introduction
09:50 - 10:00
Opening Chair
Session 1A
Chair not set
10:00 - 10:30
1A-I1
Norris, David
Optical Materials Engineering Laboratory, ETH Zürich, Switzerland
The Dream of the Perfect Nanocrystal
Norris, David
Optical Materials Engineering Laboratory, ETH Zürich, Switzerland, CH

David J. Norris received his B.S. and Ph.D. degrees in Chemistry from the University of Chicago (1990) and Massachusetts Institute of Technology (1995), respectively. After an NSF postdoctoral fellowship with W. E. Moerner at the University of California, San Diego, he led a small independent research group at the NEC Research Institute in Princeton (1997). He then became an Associate Professor (2001–2006) and Professor (2006–2010) of Chemical Engineering and Materials Science at the University of Minnesota, where he also served as Director of Graduate Studies in Chemical Engineering (2004–2010). In 2010, he moved to ETH Zurich where he is currently Professor of Materials Engineering. From 2016 to 2019 he served as the Head of the Department of Mechanical and Process Engineering. He has received the Credit Suisse Award for Best Teacher at ETH, twice the Golden Owl Award for Best Teacher in his department, the Max Rössler Research Prize, an ERC Advanced Grant, and the ACS Nano Lectureship Award. He is a Fellow of the American Physical Society and the American Association for the Advancement of Science, and an editorial board member for ACS Photonics and Nano Letters. His research focuses on how materials can be engineered to create new and useful optical properties.

Authors
David Norris a
Affiliations
a, ETH – Swiss Federal Institute of Technology Zurich, Department of Mechanical and Process Engineering, Rämistrasse, 101, Zürich, CH
Abstract

Quantum dots are nanometer-sized crystallites of semiconductor that have a roughly spherical shape. Due to extensive research, quantum dots are now commercially used as a robust fluorescent material in displays and lighting. However, even with our best procedures, state-of-the-art samples still contain particles with a distribution in size and shape. Because this causes variations in their optical properties, their performance for applications is reduced. This leads to a fundamental question: can we achieve a sample of semiconductor nanocrystals in which all the particles are exactly the same? In this talk we will discuss this possibility by examining two classes of nanomaterials. First, we will consider thin rectangular particles known as semiconductor nanoplatelets. Amazingly, nanoplatelet samples can be synthesized in which all crystallites have the same atomic-scale thickness (e.g., 4 monolayers). This uniformity in one dimension suggests that routes to monodisperse samples might exist. After describing the underlying growth mechanism for nanoplatelets, we will then move to a much older nanomaterial—magic-sized clusters (MSCs). Such species are believed to be molecular-scale arrangements (i.e., clusters) of semiconductor atoms with a specific (“magic”) structure with enhanced stability compared to particles slightly smaller or larger. Their existence implies that MSC samples can in principle be the same size and shape. Unfortunately, despite three decades of research, the formation mechanism of MSCs remains unclear, especially considering recent experiments that track the evolution of MSCs to sizes well beyond the “cluster” regime. Again, we will discuss the underlying growth mechanism and its implications for nanocrystal synthesis. Finally, we will present an outlook if perfect nanomaterials can be obtained.

10:30 - 11:00
1A-I2
Jeong, Sohee
Sungkyunkwan University, South Korea
InP tetrapods: Synthesis, surface chemistry, and optical properties
Jeong, Sohee
Sungkyunkwan University, South Korea, KR
Authors
Sohee Jeong a
Affiliations
a, Department of Energy Science, Sungkyunkwan University, 25-2 Sungkyunkwan-ro, Jongno-gu, Seoul, Corea del Sur, KR
Abstract

In the last 30 years, inorganic semiconductor nanocrystals have been extensively researched because of their size-dependent optoelectronic properties, thus successfully debuting in the commercial sector. The synthetic development of nanocrystals, however, has perplexed from the complex energy landscape of the reaction. Unlike intermediates that can be isolated and characterized with atomic precision in organic synthesis, the intermediates in nanocrystal synthesis are difficult to resolve because of the co-existence of metastable states with similar energy. If one can control the energy of the metastable intermediates originating from various factors including shapes and surface-ligand interaction and isolate the singular intermediate species, the nanocrystal growth with atomic precision could be achievable.

In this presentation, I will discuss the tetrapod InP nanocrystals as a crystalline “late intermediate” that warrants controlled colloidal nanocrystal growth. The use of the late intermediate with well-defined facets at the sub-10 nm scale for directional growth with atomic control and highlight the potential for the new directed approach of nanocrystal synthesis. Well-defined surface of tetrapod enable us to investigate the facet-dependent surface chemistry of InP. Finally, a geometry-driven transition from single to multi-photon emitting behavior in InP tetrapods will be discussed.

11:00 - 11:30
Coffee Break
Session 1B
Chair not set
11:30 - 12:00
1B-I1
Infante, Ivan
Istituto Italiano di Tecnologia (IIT)
The Emergence of Double Perovskite Nanocrystals from a Computational Standpoint
Infante, Ivan
Istituto Italiano di Tecnologia (IIT), IT
Authors
Ivan Infante a, c, d, Juliette Zito a, b, Luca De Trizio a, Liberato Manna a
Affiliations
a, Nanochemistry, Istituto Italiano di Tecnologia (IIT), via Morego 30, 16163 Genova, Italy.​
b, Dipartimento di Chimica e Chimica Industriale, Università degli Studi di Genova, Via Dodecaneso, 31, 16146, Genova, Italy​
c, BCMaterials, Basque Center for Materials, Applications and Nanostructures, UPV/EHU Science Park, Spain., Barrio Sarriena s/n, 48940 Leioa, ES
d, IKERBASQUE, Basque Foundation for Science, Plaza Euskadi 5, 48009 Bilbao, Spain
Abstract

The search for metal halide perovskite nanocrystal (NC) materials alternative to Pb-based compositions has led to the discovery of several candidates with promising optical properties. Some of the most interesting compounds synthesized so far belong to the double-perovskite (DP) family, are characterized by a general Cs2B+B3+Cl6 stoichiometry and feature a perovskite structure composed of a 3D network of [B+Cl6] and [B3+Cl6] corner-sharing octahedra, with Cs+ ions filling the voids in between. Examples are Cs2AgBiCl6, Cs2AgInCl6, Cs2NaInCl6, Cs2NaBiCl6 and Cs2AgSbCl6 NCs. These materials, especially in the NC form, generally exhibit a weak photoluminesce (PL), as they feature either an indirect bandgap or a direct bandgap with a parity forbidden transition. However, when opportunely doped/alloyed, they become more efficient emitters.

In this work, I will provide an overview of all the development in the DP field with a particular focus on the computational modelling of these materials using density functional theory (DFT) and classical molecular dynamics. I will show how integrating experiments with calculations is helpful in improving the efficiency of these materials and make them strong candidates to replace Pb-based perovskites.

12:00 - 12:30
1B-I2
even, jacky
Institut National des Sciences Appliquées, Rennes
Unusual anharmonicity and pseudospin-phonon dynamics in 3D halide perovskites
even, jacky
Institut National des Sciences Appliquées, Rennes, FR

Jacky Even was born in Rennes, France, in 1964. He received the Ph.D. degree from the University of Paris VI, Paris, France, in 1992. He was a Research and Teaching Assistant with the University of Rennes I, Rennes, from 1992 to 1999. He has been a Full Professor of optoelectronics with the Institut National des Sciences Appliquées, Rennes,since 1999. He was the head of the Materials and Nanotechnology from 2006 to 2009, and Director of Education of Insa Rennes from 2010 to 2012. He created the FOTON Laboratory Simulation Group in 1999. His main field of activity is the theoretical study of the electronic, optical, and nonlinear properties of semiconductor QW and QD structures, hybrid perovskite materials, and the simulation of optoelectronic and photovoltaic devices. He is a senior member of Institut Universitaire de France (IUF).

Authors
jacky even a, bernard hehlen b, philippe bourges c, benoit rufflé b, antoine letoublon a, marios zacharias a, claudine katan d
Affiliations
a, Univ Rennes, INSA Rennes, CNRS, Institut FOTON (Fonctions Optiques pour les Technologies de l'informatiON ) - UMR 6082, F-35000 Rennes, France
b, Laboratoire Charles Coulomb, UMR 5221, Université de Montpellier, 34095 Montpellier, France
c, Université Paris-Saclay, CNRS, CEA, Laboratoire Léon Brillouin, Rue Joliot Curie, 3, Gif-sur-Yvette, FR
d, Univ Rennes, ENSCR, INSA Rennes, CNRS, ISCR (Institut des Sciences Chimiques de Rennes) - UMR 6226, F-35000 Rennes, France
Abstract

3D halide perovskites used in light emitters and PV systems exhibit an unusual anharmonicity, which is not accounted for in nowadays descriptions of phonons and electron-phonon coupling. Therefore, the low frequency lattice vibrations and relaxations were investigated in single crystals of the four 3D hybrid organolead perovskites, MAPbBr3, FAPbBr3, MAPbI3, and FAPbI3, at the Brillouin zone center using Raman and Brillouin scattering and at the zone boundary using inelastic neutron scattering. The temperature dependence of the PbX6 lattice modes in the four compounds can be renormalized into universal curves and no soft vibration is observed excluding a displacive-like transitional dynamics related to structural phase transitions. The reorientational (pseudospin) motions of the molecular cations exhibit a seemingly order-disorder character recalling that of plastic crystals, but attributed to a secondary order-parameter. At ultra-low frequency, a quasi-elastic component evidenced by Brillouin scattering and associated to the unresolved central peak observed in neutron scattering, is attributed to center of mass anharmonic motions and rattling of the molecular cations in the perovskite cavities. 3D halide perovskites are therefore in a very unusual situation where anharmonicity prevails. It is leading to partial, extensive and ultraslow critical and stochatic dynamics connected to structural instabilities. The extensive disorder of the lattice at normal operation temperatures for devices is similar to premelting where only long-range acoustic normal modes survive.  

Acknowledgments

The research leading to these results has received funding from the European Union’s Horizon 2020 program, through a FET Open research and innovation action under the grant agreement No 899141. (POLLOC).

12:30 - 13:00
1B-I3
Tamarat, Philippe
LP2N - Institut d'Optique, Université de Bordeaux & CNRS
Band-Edge Exciton Fine Structure and charge-carrier interactions in Lead-Halide Perovskite Nanocrystals
Tamarat, Philippe
LP2N - Institut d'Optique, Université de Bordeaux & CNRS, FR
Authors
Philippe Tamarat a
Affiliations
a, LP2N, Univ. Bordeaux, IOGS &CNRS, Talence (France)
Abstract

Lead-halide perovskite nanocrystals (NCs) have emerged as attractive nano-building blocks for photovoltaics and optoelectronic devices. Optimization of perovskite NC-based devices relies on a better knowledge of the fundamental electronic and optical properties of the band-edge exciton, whose fine structure has long been debated. This talk will give an overview of our recent magneto-optical spectroscopic studies [1-5] revealing the entire excitonic fine structure and relaxation mechanisms in these materials, using a single-NC approach to get rid of the inhomogeneities in the NC morphologies and crystal structures. Moreover, it will highlight universal scaling laws relating the exciton fine structure splitting, the trion and biexciton binding energies to the band-edge exciton energy in lead-halide perovskite nanocrystals, regardless of their chemical composition (inorganic and hybrid organic-inorganic, as well as mixed halide alloys) and their spectral emission range (from the blue to the near infrared). These scaling laws offer a general predictive picture for the charge-carrier interactions in these emerging materials, from the bulk regime to the regime of highly confined carriers.

13:00 - 13:30
1B-I4
Chamarro, Maria
Sorbonne Universite
EXCITON PROPERTIES of CSPBCL3 HALIDE PEROVSKITES
Chamarro, Maria
Sorbonne Universite, FR

Maria Chamarro is Professor in Physics at Sorbonne University, France and member of the Paris Institute of Nanosciences (INSP). She received her PhD in Physics (Optics speciality) form Zaragoza University, Spain, in 1989. Since 2021 she is a member of the French Committee for Scientific Research (five years) a position that she already occupied in the previous years (1995-2000). From 2012 to 2014 she was member of ‘Directory of Research’ at Pierre and Marie Curie University (now Sorbonne University). Her area of expertise is the experimental study of condensed matter electronic properties. In particular, she was interested in the spectroscopy of glasses doped with transition metals or rare earths, and the optical properties and relaxation dynamics of electronic excitations in semiconductor nanostructures. She was co-head of the "Spin Dynamics" team at INSP where she worked in the optical orientation and the all-optical manipulation of electron spin confined in a semiconductor quantum dot. In this framework, she developped ultrafast optical spectroscopies based on the photo-induced Faraday and Kerr effects. Now she coordinates a research project centred on the study of perovskite nanocrystals for nanophotonics applications.

Authors
Michal Baranowski a, Victor Guilloux b, Paulina Plochocka a, c, Riu SU d, Laurent Legrand b, Thierry Barisien b, frederick Bernardot b, Qihua Xiong e, Christophe Testelin b, Maria Chamarro b
Affiliations
a, 1Department of Experimental Physics, Faculty of Fundamental Problems of Technology, Wroclaw University of Science and Technology, wybrzeże Stanisława Wyspiańskiego, 27, Wrocław, PL
b, 2Sorbonne Université, CNRS-UMR 7588, Institut des NanoSciences de Paris, INSP, Place Jussieu, 4, Paris, FR
c, Laboratoire National des Champs Magnétiques Intenses, UPR 3228, Rue de Grenoble, Toulouse, FR
d, Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, Nanyang Avenue, 50, Singapore, SG
e, Division of Quantum State Matter, Physics Departement, Tsinghua University, Chine, Shuang Qing Lu, CN
Abstract

In the past few years, lead-halide perovskites have appeared as a new generation of promising semiconductor materials for photovoltaic and optoelectronic applications. Belonging to this family, CsPbCl3 have the largest energy band gap showing an absorption threshold and photoluminescence in the blue spectral region.

As a representative of this new class, CsPbCl3 has the largest energy band gap, hence showing an absorption threshold and a photoluminescence emission in the blue spectral region. The manifestation of polaritonic effects at room temperature makes it a privileged candidate for new photonic devices and suggests moreover that excitons are particularly robust [1]. 

Here we present the results of high magnetic field spectroscopy on bulk CsPbCl3 thin films that allow to obtain the fundamental exciton parameters, as the exciton binding energy, the effective mass, dielectric constant and Landé factors. We confirm the strong value of the exciton binding energy that makes it very stable at room temperature. We compare our results with results obtained by other authors in a wide range of different halide perovskites and we provide evidence of universal laws according to the gap energy. In particular the binding energy law is obtained by comparing perovskite compounds and other more conventional semiconductor materials [2].

The electron-hole exchange interaction related to Coulomb interaction is responsible in semiconductors of the splitting of the lowest-energy degenerate exciton state leading to the so-called exciton fine structure(EFS). Taking into account the measured excitonic parameters in bulk CsPbCl3 we will finally discuss the EFS of CsPbCl3 nanocrystals considering symmetries, shape anisotropy and environmental parameters. 

13:30 - 15:00
Lunch Break
Session 1C1
Chair not set
15:00 - 15:15
1C1-O1
Protesescu, Loredana
University of Groningen, The Netherlands
Chemical design for metal halide perovskites nanostructures
Protesescu, Loredana
University of Groningen, The Netherlands, NL
Authors
Loredana Protesescu a
Affiliations
a, Zernike Institute for Advanced Materials, University of Groningen, The Netherlands, Nijenborgh, 7, Groningen, NL
Abstract

Metal halides perovskites with nanoscale geometries have revolutionized the field of solution-processed photovoltaics and light-emitting devices due to their strong absorption and exceptional photoluminescence properties combined with a remarkable tolerance to structural defects. However, the further development of these materials to practical commercialization is hindered by their toxic components like lead and their inherent structural lability. Moreover, we still have little understanding of their crystallographic structures, chemical and physical interactions, and surface chemistry at a fundamental level.

The chemical design of metal halide perovskites proved to be the key to addressing those issues. Our recent findings confirm that a direct transition of the synthetic approach at nanoscale from Pb to Sn halide perovskites is not feasible. For Sn-based perovskites nanostructures, the structural dynamics between 3D cuboids and 2D Ruddlesden-Popper nanosheets colloids are highly dependent on the synthetic strategy. The presence of both species has a direct impact on the optoelectronic properties. Moreover, heterostructures containing halide perovskites nanocrystals are the next step towards obtaining accessible materials for industry. With the help of polymers or metal-organic frameworks,  we can access air stable materials or ultra-small quantum dots.

15:15 - 15:30
1C1-O2
Zacharias, Marios
INSA Rennes
Electron-phonon physics in cubic halide perovskites: The role of disorder
Zacharias, Marios
INSA Rennes, FR

Marios Zacharias is currently a post-doctoral researcher at FOTON institute, INSA, Rennes working with Profs. Jacky Even and Laurent Pedesseau for the European project DROP-IT [1]. He earned his Ph.D. in Materials Science at Oxford University, United Kingdom (2017) and held a post-doctoral appointment at Oxford University (2018), under the supervision of Prof. F. Giustino. In 2019, he joined the NOMAD laboratory of Prof. M. Scheffler at Fritz Haber Institute in Berlin. From 2020 to 2021, he moved to Cyprus University of Technology and led the simulation group of RUNMS of Prof. P. C. Kelires. His research interests focus on electronic structure theory and the development of new first-principles techniques for the accurate and efficient description of vibrational, electron-phonon, and vibronic physics of quantum materials. He is the developer of the software package EPW/ZG in Quantum Espresso. He has developed the special displacement method (SDM) [2] and stAVIC [3] approaches for electronic structure calculations at finite temperatures. Recently, Marios has introduced an approach for the calculation of multiphonon diffuse scattering allowing for the interpretation of thermal and time-resolved phenomena in solids [4]. He is currently working on the efficient treatment of anharmonicity in halide and oxide perovskites.

[1] https://cordis.europa.eu/project/id/862656
[2] Phys. Rev. Res. 2, 013357 (2020)
[3] Phys. Rev. B 102, 045126 (2020)
[4] Phys. Rev. Lett. 127, 207401 (2021)
 

Authors
Marios Zacharias a, Jacky Even a
Affiliations
a, Université Rennes, INSA Rennes, CNRS, Institut FOTON, Place Recteur Henri le Moal, Rennes, FR
Abstract

State-of-the-art first-principles calculations for cubic halide perovskites are performed by assuming that the potential energy felt by electrons is described with the nuclei clamped at their crystallographic positions. This assumption inevitably misses the effect of structural disorder which is ubiquitous in this class of materials, affecting their light-absorbing and emitting properties. Here, we demonstrate the important role of disorder in the electron-phonon physics of cubic perovskites, starting first from its distinct effect on the electronic structure and lattice dynamics. We show that ground-state structural deformations yield large renormalization of the bandgap, dielectric constant, and effective charges, as well as lead to dynamically stable phonons. We include electron-phonon dynamics in our calculations via the special displacement method and show that disorder is critical in the evaluation of phonon-induced bandgap renormalization. We also demonstrate that the effect of disorder is central to diffuse scattering, opening the way to interpret time-resolved phenomena manifested in X-ray or electron diffraction experiments.

15:30 - 15:45
1C1-O3
JIANG, Pingping
Univ Rennes, INSA Rennes, CNRS, Institut FOTON - UMR6082, France
Influence of surface termination on the structural and electronic properties at the Pb-free perovskite/charge transport material interfaces
JIANG, Pingping
Univ Rennes, INSA Rennes, CNRS, Institut FOTON - UMR6082, France, FR

I am a enthusiasm and active learner who wishes to travel in the knowledge ocean. I had my bachlor and master diplomats in Nanchang Hankong Univ. and Huazhong Sicence & Technology Univ. in China respectively, and then got my phD diplomat in Aix-marseille Univ. in France. Right now I am working in INSA Rennes at FOTON lab, mainly focusing on the surface and interface enginnering of lead-free perovskites together with different charge transport materials by using DFT calculation.

Authors
Pingping JIANG a, Boubacar TRAORE b, Mikael KEPENEKIAN b, George VOLONAKIS b, Claudine KATAN b, Laurent PEDESSEAU a, Jacky EVEN a
Affiliations
a, Université Rennes, INSA Rennes, CNRS, Institut FOTON, Place Recteur Henri le Moal, Rennes, FR
b, Univ Rennes, ENSCR, INSA Rennes, CNRS, ISCR (Institut des Sciences Chimiques de Rennes) - UMR 6226, F-35000 Rennes, France
Abstract

To cope with the toxicity of Pb-based perovskites and achieve smaller electronic band gaps, replacing Pb with Sn has gained growing attention recently 1,2. Importantly, the low-bandgap Pb-Sn alloyed perovskite allows the building of all-perovskite tandem solar cells that shall overcome the performances of single-junction perovskite cells 3,4. In fact, of all possible means to improve perovskite film quality and suppress nonradiative recombination in optoelectronic devices for a high photo conversion efficiency purpose, the surface and interface functionalizations after the assembly with charge transport layer (CTL) are one of the most critical parameters 5,6. In view of the sophisticated chemical and physical properties of Sn-based perovskites, theoretical calculations based on density functional theory (DFT) provide a useful insight into the interplay between absorbers and CTLs. Here, FASnI3 is chosen as a benchmark material. We thoroughly investigate the influence of its surface termination on structural and electronic properties when interfacing with organic C60 (100) and inorganic SnO2 (100) and (110), including the intermediate work function calculations on the free-standing slabs. Based on the theoretical methodology developed in our team7, we have evidenced the proportionality between work function shifts and surface dipoles, making the optimization of interfacial charge transport possible by surface dipole tuning. Our findings on the charge transport properties of the two targeted CTLs, contribute to analyzing promising alternatives as CTLs for Pb-free perovskites thanks to the surface and interface engineering.

15:45 - 16:00
1C1-O4
Stelmakh, Andriy
ETH Zurich, Laboratory of Inorganic Chemistry, Department of Chemistry & Applied Biosciences
Structurally Tailored Zwitterionic Phospholipid Capping Ligands for Lead Halide Perovskite Nanocrystals
Stelmakh, Andriy
ETH Zurich, Laboratory of Inorganic Chemistry, Department of Chemistry & Applied Biosciences, CH
Authors
Viktoriia Morad a, b, Andriy Stelmakh a, b, Mariia Svyrydenko a, b, Leon Feld a, b, Marcel Aebli a, b, Andrij Baumketner c, Maksym Kovalenko a, b
Affiliations
a, Laboratory of Inorganic Chemistry, Department of Chemistry and Applied Biosciences, ETH Zürich, CH-8093 Zürich, Switzerland
b, Laboratory of Thin Films and Photovoltaics, Empa – Swiss Federal Laboratories for Materials Science and Technology, Dübendorf, Switzerland, Ueberlandstrasse, 129, Dübendorf, CH
c, Institute for Condensed Matter Physics, NAS of Ukraine, Lviv 79011, Ukraine
Abstract

Versatile surface functionalization of highly ionic surfaces, ubiquitous among inorganic nanomaterials, remains a formidable challenge in the view of inherently non-covalent surface bonding.[1] Colloidal lead halide perovskite nanocrystals (NCs), which are of interest for classical and quantum light generation,[2,3] are one of the examples. Despite some recent empirical progress in surface chemistry of lead halide perovskite NCs, the general strategy towards their robust surface functionalization still remains a challenge. In this study we present the first structural investigation of perovskite surfaces capped with zwitterionic phospholipid molecules. In line with molecular dynamics simulations and solid-state NMR, zwitterionic phospholipid ligands bind to the perovskite surfaces with both head-groups, thus hindering their desorption. Furthermore, the ligand head-group affinity to the surface is primarily governed by geometric fitness of its cationic and anionic moieties into the crystal lattice. As a result, stable and colloidally robust nanocrystals of inherently soft and chemically labile lead halide perovskites – FAPbX3 and MAPbX3 (X – Br, I) – can be obtained with a lattice-matched phosphoethanolamine head-group. Stable surface passivation is also reflected in excellent optical properties of the NCs. As an example, alkylphospholipid-capped FAPbBr3 NCs display a stable emission with near unity photoluminescence quantum yield in a broad concentration range, as well as in thick films. Ligand tail engineering, on the other hand, allows diverse surface functionalization of the NCs, broadening the scope of their potential applications.

16:00 - 16:15
1C1-O5
Gualdrón-Reyes, Andres F.
Universitat Jaume I, Institute of Advanced Materials (INAM) - Spain
Recent strategies to suppress the iodide deficiency in APbI3 (A = Cs+, FA+) perovskite nanocrystals: ligand and doping engineering
Gualdrón-Reyes, Andres F.
Universitat Jaume I, Institute of Advanced Materials (INAM) - Spain, ES
Authors
Andres F. Gualdrón-Reyes a, Sofia Masi a, Iván Mora-Seró a
Affiliations
a, Institute of Advanced Materials (INAM), Universitat Jaume I, Avinguda de Vicent Sos Baynat, Castelló de la Plana, ES
Abstract

Halide perovskite nanocrystals (PNCs) are prominent and interesting nanomaterials for actively studying photovoltaics, optoelectronics, photonics, and solar-driven chemistry. Valuable features including easy preparation, narrow width at half-maximum photoluminescence (PL) peak, adjustable/modifiable surface chemistry, a notable PL quantum yield (PLQY) of up to 100%, and a modulable band gap have been exploited to fabricate highly efficient devices such as PNC solar cells and multiple color light-emitting diodes (LEDs). Despite of above benefits of the PNCs, the PLQY and material quality are limited by their defective structure, making them prone to degradation. Factors such as (i) synthetic protocols for the PNCs formation and (ii) the loss of capping ligands from PNCs surface are pivotal to create a defective structure. In both cases, halide deficiency is the main reason to cause the appearance of a high density of nonradiative recombination sites, reducing the stability of the final product, and hindering the effective extraction of charge carriers. To overcome these drawbacks, we have analyzed the influence of the synthesis temperature, ligand concentration and metal doping engineering on the enhancement of the photophysical properties, stability, and suppression of non-radiative carrier traps of red-emitting APbI3 (A= Cs+, FA+) PNCs. By establishing an efficient surface passivation through ligand coverage [1] and the incorporation of Sr to substitute Pb during the PNCs synthesis [2], less defective PNCs are formed, with long-term stability around 15 months, providing a pure deep red tonality. Therefore, it is possible to produce excellent candidates to improve the performance of optoelectronic devices and to conduct lead solar driven processes more efficiently.

16:15 - 16:30
1C1-O6
Hadar, Ido
The Hebrew University of Jerusalem
White Light Emission from Low Dimensionality Halide Perovskites
Hadar, Ido
The Hebrew University of Jerusalem, IL

Current Position:

2020-Present – Senior Lecturer of Chemistry – Institute of Chemistry and The Center for Nanoscience and Nanotechnology, The Hebrew University of Jerusalem, Israel

Research Objectives:

Research and development of novel soft-semiconductors for light emission and X-ray detection

Research of novel soft-semiconductor materials and development of functional devices based upon them

Study fundamental processes and basic properties of functional materials – optical and electrical spectroscopy and microscopy

Development of composite semiconductors and devices based upon them

Education:

2016-2020 – Post-doctoral scholar – "Research and Development of Low-Cost and Air-Stable Solar Cells, Detectors and Light Emitting Devices" – Prof. Mercouri Kanatzidis Lab, Department of Chemistry, Northwestern University (Evanston, IL, USA)

2011–2016 – Ph.D. – Physical Chemistry – "Dimensionality Effects in Semiconductor Nanorods – Optical Study from Single Particles to Ensemble" – under the supervision of Prof. Uri Banin, The Hebrew University of Jerusalem (IL)

2010-2011 – M.Sc. (within the direct Ph.D. track) – Exact Science, The Hebrew University of Jerusalem (IL)

2006-2009 – B.Sc. – Exact Science (Physics and Chemistry), The Hebrew University of Jerusalem (IL)

Authors
Ido Hadar a
Affiliations
a, Institute of Chemistry and the Center for Nanoscience and Nanotechnology, The Hebrew University of Jerusalem, Mount Scopus Jerusalem
Abstract

Hybrid halide perovskites are a novel class of semiconductor materials with promising and versatile optoelectronic properties, enabled by their chemically adjustable structures and dimensionality. The diversity in the metal ions, halide anions, and organic spacers enables a wide range of materials with highly tunable properties and variable dimensionalities. These materials are studied for various applications such as solar cells, detectors, and light-emitting diodes. The ability to control and adjust the optical properties for a required application is significant. Thus, an improved understanding of the structure and optical mechanisms is crucial.

Specific low-dimensionality hybrid halide perovskites exhibit white-light emission at room temperature, associated with self-trapped excitons (STE), making them ideal candidates for illumination applications. We study the correlation between structural motifs of low dimensionality (2D, 1D) halide perovskites and their STE emission. We further study how the composition and specifically exchanging the halide anions while maintaining the structure affect the STE properties.

Session 1C2
Chair not set
15:00 - 15:15
1C2-O1
De Trizio, Luca
Istituto Italiano di Tecnologia (IIT)
ZnCl2 Mediated Synthesis of InAs Nanocrystals with Aminoarsine
De Trizio, Luca
Istituto Italiano di Tecnologia (IIT), IT
Authors
Dongxu Zhu a, Houman Jalali a, Francesco Di Stasio a, Mirko Prato a, Iurii Ivanov a, Giorgio Divitini a, Ivan Infante a, Liberato Manna a, Luca De Trizio a
Affiliations
a, Istituto Italiano di Tecnologia,, Genova, IT
Abstract

Colloidal semiconductor nanocrystals (NCs) emitting in the near-infrared (NIR) are of particular interest as they can find application in telecommunications to night vision, photovoltaics, lasing, and in vivo biological imaging.[1] Since the most developed NIR emitting materials are very toxic, being Pb- or Hg-based chalcogenides, the current trend is to move toward compounds being RoHS (European “Restriction of Hazardous Substances”) compliant.[2] In this context, the most promising NIR candidates are InAs NCs whose bandgap can be tuned from the visible up the the whole NIR range. Currently, the most advanced colloidal strategies for InAs NCs rely on pyrophoric, toxic and not commercially available tris-trimethylsilyl arsine (or derivatives).[3] Therefore, in recent years alternative synthesis routes based on less toxic and commercially available As precursors, such as tris(dimethylamino)arsine (amino-As), have been explored.[4] Such procedures deliver InAs NCs that need to be further optimized in terms of size distribution and optical properties, in order to meet the standard reached with tris-trimethylsilyl arsine. To this aim, in this work we show that the use of ZnCl2 as an additive in the synthesis of such NCs (based on amino-As  and alane N,N-dimethylethylamine as the reducing agent) leads to two important achievements: i) helps to improve the size distribution of InAs NCs; ii) allows for the in-situ formation of bright emissive InAs@ZnSe core@shell NCs, with photoluminescence quantum yield ≥40%.[5] The results of this study open new perspectives for the production of efficient InAs-based NC systems with amino-As and, consenquently, for their exploitation in optoelectronic devices.

15:15 - 15:30
1C2-O2
Keivanidis, Panagiotis E.
Cyprus University of Technology
Fusion of Triplet Emissive States as a Tool to Drive Photocurrent Generation in Vertically-configured Organic Photodetectors
Keivanidis, Panagiotis E.
Cyprus University of Technology, CY
Authors
Giannis Antoniou a, Yuan Peisen a, Loukas Koutsokeras a, Stavros Athanasopoulos b, Daniele Fazzi c, Themis Prodromakis d, Julianna Panidi d, Dimitra G. Georgiadou d, Panagiotis E. Keivanidis a
Affiliations
a, Device Technology and Chemical Physics Lab, Department of Mechanical Engineering and Materials Science and Engineering, Cyprus University of Technology, Archiepiskopou Kyprianou, 30, Limassol, CY
b, Departamento de Física, Universidad Carlos III de Madrid, Avenida de la Universidad, 30, Leganés, ES
c, Dipartimento di Chimica "Giacomo Ciamician”, Università di Bologna, Via Zamboni, 33, Bologna, IT
d, Centre for Electronics Frontiers, Electronics and Computer Science, University of Southampton, University Road, GB
Abstract

The integration of triplet-triplet annihilation (TTA) components as electrically and optically active elements in vertically-structured photoactive device architectures is a challenging task to achieve. Herein we present a simple methodology for incorporating a photon absorbing layer of the (2,3,7,8,12,13,17,18-octaethyl-porphyrinato) platinumII (PtOEP) metallorganic complex, as a self-TTA annihilator medium in a vertically stacked photodiode device structure. At low-power illumination, the PtOEP photodiode exhibits photocurrent generation via the fusion of optically-induced PtOEP excited states and it develops an open-circuit voltage as high as 1.15 V. The structural and spectroscopic characterization of the nanostructured PtOEP photoactive layer in combination with electronic structure calculations identify emissive PtOEP dimer species as the annihilating excited state responsible for the formation of charges. The participation of the fusion process in the mechanism of charge photogeneration manifests in the supralinear dependence of the short-circuit current density on the incoming photoexcitation intensity, both when incoherent and coherent light is used for illuminating the PtOEP photodiode. The photoresponse of the PtOEP device allows for the highly selective and sensitive photodetection within the 500 - 560 nm narrow spectral range. At short-circuit conditions a power-law is observed in the dependence of the device responsivity on fluence. Based on a scrutinized device engineering methodology the PtOEP annihilator is further utilized for stimulating the response of UV-only organic photodetector with visible light. In overall, these findings propose that triplet-excited annihilator species with appropriately selected frontier orbital energetics are valuable photoactive components, capable to extend the photosensitivity spectral window of electronic devices with a vertically-configured device structure.

15:30 - 15:45
1C2-O3
Montanarella, Federico
Nano-Engineered Phosphors for (Micro)LEDs
Montanarella, Federico
Authors
Federico Montanarella a, Atul Sontakke a, Vasilii Khanin a, Anne Berends a, Valerio Favale a, Mohamed Tachikirt a, Mike Krames a, Marie Anne van de Haar a
Affiliations
a, Seaborouh B.V., Science Park 106, Amsterdam, NL
Abstract

Narrow-band line-emitter phosphors have enormous potential for use in LEDs, as they offer improved luminous efficacy (lm/W) for white LEDs, while maintaining high color rendering (CRI>90). Especially trivalent Eu-doped phosphors are ideal from an emitter perspective, due to their efficient and extremely narrow-band emission in the red spectral region. However, the major bottleneck for implementation of these phosphors in LEDs, is the lack of absorption in the blue spectral region. To solve this problem, we have been exploring nano-engineered interparticle energy transfer (IFRET), an innovative approach to decouple emission and excitation properties.1 Even though IFRET would enable the use of trivalent lanthanide-doped phosphors for solid state lighting applications in general, the nanoscale components of IFRET materials are more broadly of interest for next generations LEDs, as cutting-edge LED technology is moving towards micro-devices.

IFRET technology allows for almost independent engineering of the emission and excitation properties to harness the best properties of each phosphor material, as you can have two different materials acting as a sensitizer and emitter. This does, for example, enable blue-sensitization of Eu3+-doped materials. Harnessing IFRET and successful implementation in commercial devices require nanoscale control over very high quality nanomaterials. Especially Ce-doped nano-YAG is of interest for LED applications, due to its very stable and efficient emission, and strong absorption in the blue spectral range. However, this material is particularly challenging to make at the nanoscale.2 We have been developing high-quality (i.e. high absorption and quantum yield) nanophosphors, including nano-YAG, that could be implemented in IFRET applications and/or small-size LEDs.

These innovations could find applications beyond lanthanide doped phosphors, by combining these more conventional materials with new cutting-edge technologies like quantum dots. Furthermore the applications could go well beyond LEDs, including sensing, medical imaging, solar and displays. In this talk we will present our latest technological developments by discussing the underlying physics, progress and challenges in achieving nano-engineered phosphors for practical LEDs.

15:45 - 16:00
1C2-O4
Kazlauskas, Karolis
Vilnius University
High Triplet Energy Hosts for Blue Thermally Activated Delayed Fluorescence OLEDs
Kazlauskas, Karolis
Vilnius University, LT
Authors
Karolis Kazlauskas a, Dovydas Banevičius a, Gediminas Kreiza a, Saulius Juršėnas a, Francesco Rodella b, Peter Strohriegl b
Affiliations
a, Institute of Photonics and Nanotechnology, Vilnius University, Lithuania, Saulėtekio av. 3, LT-10257 Vilnius,, LT
b, Macromolecular Chemistry I, University of Bayreuth, Germany, Bayreuth, DE
Abstract

The last decade has witnessed a huge progress in thermally activated delayed fluorescence (TADF) emitters employed for fabrication of the latest generation OLEDs.[1,2] TADF allows harvesting of up to 100% triplet excitons through reverse intersystem crossing (RISC) process in organic materials without employing precious metals, thus rivalling the efficiencies of state-of-the-art phosphorescent OLEDs.[3,4] Even though TADF-OLEDs have demonstrated an upper limit of internal quantum efficiency (100%) across the whole visible range, their short operational lifetime in the blue range restricts the development and commercialization of these devices.[5] Half-life of blue-emitting devices typically does not exceed a few hours at a practical luminance of 1000 cd/m2.[6] Among the key factors affecting the device stability are the degradation of TADF emitter and host material.

The design of efficient blue emitter–host combinations is one of the greatest challenges in organic light-emitting diode (OLED) research. The choice of the host material crucially affects device efficiency, roll-off and lifetime. High triplet energy hosts are in high demand, especially for thermally activated delayed fluorescence (TADF) emitters, due to their high exciton energies. The hosts are far less investigated than the emitters and require further progress.[7]

In this work, we introduce two novel hosts based on acridine donor and triazine acceptor (ATRZ) exhibiting good thermal and morphological properties and high triplet energies 3.07-3.27 eV. The donor and acceptor combination enables transport of both electrons and holes. Application of these bipolar hosts in blue TADF-OLEDs resulted in a blue electroluminescence peaking at 480-488 nm, a maximum EQE of 10%, and a low efficiency roll-off. The device based on ATRZ host was found to express the highest stability, i.e. the longest operational lifetime, which even surpassed that of OLED based on the benchmark mCBP host.

16:00 - 16:15
1C2-O5
Rodà, Carmelita
Gent University, Department of Chemistry, BE
Area-Independent Biexciton Oscillator Strength in Colloidal Nanoplatelets
Rodà, Carmelita
Gent University, Department of Chemistry, BE, BE
Authors
Carmelita Rodà a, Pieter Geiregat a, Alessio Di Giacomo a, Iwan Moreels a, Zeger Hens a
Affiliations
a, Physics and Chemistry of Nanostructures, Department of Chemistry, Ghent University, Ghent, Belgium
Abstract

Colloidal nanoplatelets (NPLs) offer the unique opportunity to investigate at room temperature excitonic light-matter interactions in two-dimensional (2D) materials. Recently, we showed that center-of-mass localization accounts for the experimental exciton radiative lifetime at room temperature, which is constant for NPLs of different area S and far slower than expected based on the giant oscillator strength fX,tot of exciton absorption.[1] On the other hand, the biexciton oscillator strength fBX in 2D materials is uniquely linked to the biexciton extension SBX, which is the area covered by the average interdistance aBX of the interacting excitons. Since aBX is an internal coordinate, fBX should thus be intrinsically independent from S and not be diminished by center-of-mass related localizations. Here, we assess this predicted scaling on a set of 4.5 ML CdSe NPLs of increasing S using circularly-polarized transient absorption (TA) spectroscopy. We confirm that the direct exciton-to-biexciton transition yields a photo-induced absorption band in the TA spectrum. Moreover, using quantitative TA spectroscopy, we demonstrate that fBX  is indeed area-independent and is approximately smaller than fX,tot by a factor aBX2/S. Interestingly, we find that SBX is comparable to the room-temperature exciton coherence area, suggesting that the radiative recombination rates of the biexciton and the localized exciton are similar. Since fBX governs absorption, emission and stimulated emission through the exciton/biexciton transition, these results underscore the relevance of this transition for the opto-electronic characteristics of 2D NPLs. Moreover, the approach to quantify the exciton/biexciton transition introduced here provides a means to rank such transitions in different 2D materials and to verify biexciton descriptors predicted from theory.

16:15 - 16:30
1C2-O6
Sánchez- Alarcón, Raúl Ivan
Instituto de Ciencia de Materiales(ICMUV), Universitat de Valencia, 46980 Paterna, Spain
Bottom-up synthesis of orange- red emitting two dimensional 2- thiophene ethyl ammonium tin(II) halide perovskite microcrystals
Sánchez- Alarcón, Raúl Ivan
Instituto de Ciencia de Materiales(ICMUV), Universitat de Valencia, 46980 Paterna, Spain, ES
Authors
Raúl Ivan Sánchez- Alarcón a, Omar Eduardo Solís- Luna a, Cristina Momblona a, Teresa S. Ripollés a, Rafael Abargues a, Pablo P. Boix a, Setatira Gorji a, Guillermo Muñoz a, Vladimir Chirvony a, Juan P. Martínez- Pastor a, Hamid Pashaeiadl a
Affiliations
a, Instituto de Ciencia de los Materiales, Carrer del Catedrátic José Beltrán Martinez, Universidad de Valencia, ES
Abstract

Tin based halide perovskites have drawn attention in the last years because of their unique combination of interesting physical properties and low toxicity, showing a great potential for solar cells, photodetectors, sensors, lasers, and light emitting diodes applications [1,7]. However, the development of electronic devices has been hindered, in part, for the poor stability of Sn (II) against atmospheric conditions (moisture and oxygen) [2]. Currently, 2D- hybrid perovskite materials were proposed to overcome these issues owing to the hydrophobic nature of large organic cations, isolating tin halide octahedrons from the moisture [3]. Among the organic cations that have been tested for 2D perovskite structures, 2- thiophene ethyl ammonium tin (II) iodide (TEA2SnI4) perovskite has shown high exciton energy binding, and low exciton- phonon interactions [4]. Although there are some published papers about TEA2SnI4 thin films [5] and nanoplates[6,8], the development of nano- and microcrystals have been limited due to fast crystallization rate of tin-based perovskites and stability issues [7]. Moreover, in the literature there are few optical and structural information about TEA2SnBr4 and TEA2SnCl4. In this work we report by first time the synthesis of TEA2SnX4 (X= Cl, Br, I) microcrystals by mean of hot injection method. We observed that the optical and structural properties of TEA2SnX4 (X= Cl, Br, I) microcrystals are dependent of the molar ratio of 2-thiophene ethyl amine and SnX2-Trioctyl phosphine (TOP) precursor solutions. In all of cases we observe a X ray diffraction pattern characterized for strong (00l; l= 2,4,6 and 8) reflections which is consistent with the quantum well like structure of 2D hybrid tin halide perovskites. However, for the synthesis of TEA2SnBr4 microcrystals, d- spacing decrease from 1.8658 nm to 1.5782 nm when the rTEA/Sn molar ratio of TEA/Sn(II) precursors decrease from 2 to 0.25. We hypothesized that at high rTEA/Sn, TEA molecules might dimerize by oxidative polymerization reaction, obtaining a long chain diammonium cation between [SnBr6]4- sheets. Evidence from 13 C nuclear magnetic resonance experiments might confirm this mechanism. TEA2SnCl4 and TEA2SnBr4 show a photoluminescence spectrum characterized by a broad band emission centred at 595 nm and 608 nm respectively. Owing to the Stoke shift between PL excitation and emission spectra of TEA2SnCl4 and TEA2SnBr4 are 318 nm and 335 nm, PL emission of this materials might be related to self- confined excitons. In the case of TEA2SnI4 microcrystals, PL emission and excitation spectra is equal to previous works [6,8], represented by a sharp band emission centred at 641 nm with a FWHM = 40 nm, and a low PLQY = 1%. We measured a high PLQY= 50% for TEA2SnBr4 microcrystals and PLQY= 20% for TEA2SnCl4 microcrystals synthesized at a high molar ratio of TEA/Sn (II) of 2. By first time, we have also demonstrated photoconductivity effect for TEA2SnI4 films containing microcrystals synthesized with a molar ratio TEA/Sn(II)= 0.5.

17:00 - 18:00
Workshop "Art of Scientific Publishing"
20:00 - 23:00
Social Dinner
 
Tue Oct 04 2022
09:55 - 10:00
nanoGe Introduction
Session 2A
Chair not set
10:00 - 10:30
2A-I1
Tisdale, William
Massachusetts Institute of Technology (MIT)
Persistent Enhancement of Exciton Diffusivity in CsPbBr3 Nanocrystal Solids
Tisdale, William
Massachusetts Institute of Technology (MIT), US

Will Tisdale joined the Department of Chemical Engineering at MIT in January, 2012, where he holds the rank of Associate Professor and is currently the ARCO Career Development Professor in Energy Studies.  He earned his B.S. in Chemical Engineering from the University of Delaware in 2005, his Ph.D. in Chemical Engineering from the University of Minnesota in 2010, and was a postdoc in the Research Laboratory of Electronics at MIT before joining the faculty in 2012. Will is a recipient of the Presidential Early Career Award for Scientists and Engineers (PECASE), the DOE Early Career Award, the NSF CAREER Award, an Alfred P. Sloan Fellowship, the Camille Dreyfus Teacher-Scholar Award, the AIChE Nanoscale Science & Engineering Forum Young Investigator Award, and MIT’s Everett Moore Baker Award for Excellence in Undergraduate Teaching.

Authors
William Tisdale a
Affiliations
a, MIT - Massachusetts Institute of Technology, Massachusetts Avenue, 77, Cambridge, US
Abstract

In semiconductors, exciton or charge carrier diffusivity is typically described as an inherent material property. Here, we show that the transport of excitons, which are bound electron-hole pairs, in CsPbBr3 perovskite nanocrystals (NCs) depends markedly on how recently those NCs were occupied by a previous exciton. Using fluence- and repetition-rate-dependent transient photoluminescence microscopy (TPLM), we visualize the effect of excitation frequency on exciton transport in CsPbBr3 NC solids. Surprisingly, we observe a striking dependence of the apparent exciton diffusivity on excitation laser power that does not arise from nonlinear exciton-exciton interactions nor from thermal heating of the sample. Upon photoexcitation, NCs transition to a transient configuration exhibiting an order-of-magnitude faster exciton transport rate. The transient configuration persists for ~microseconds at room temperature, and does not depend on the identity of surface ligands or presence of an oxide shell, suggesting that it is an intrinsic response of the perovskite lattice to electronic excitation. The finding of a transient enhancement in excitonic coupling between NCs may help explain other extraordinary photophysical behaviors observed in CsPbBr3 NC arrays, such as superfluorescence. Additionally, faster exciton diffusivity under higher photoexcitation intensity is likely to provide practical insights for optoelectronic device engineering.

10:30 - 11:00
2A-I2
NGUYEN, Tan
Many-body physics of emission from excitonic complexes in cesium lead halide perovskite quantum dots
NGUYEN, Tan
Authors
Tan NGUYEN a, Chenglian ZHU b, c, Simon BOEHME b, c, Anastasiia MOSKALENKO b, c, Dmitry DIRIN b, c, Maryna BODNARCHUK b, c, Gabriele RAINO b, c, Maksym KOVALENKO b, c, Claudine KATAN a, Jacky EVEN d
Affiliations
a, Univ Rennes, ENSCR, INSA Rennes, CNRS, ISCR (Institut des Sciences Chimiques de Rennes) - UMR 6226, F-35000 Rennes, France
b, Institute of Inorganic Chemistry, Department of Chemistry and Applied Biosciences, ETH Zürich, CH-8093 Zürich, Switzerland
c, Laboratory for Thin Films and Photovoltaics, Empa Swiss Federal Laboratories for Materials Science and Technology, 8600 Dübendorf, Suiza, Dübendorf, CH
d, Univ Rennes, INSA Rennes, CNRS, Institut FOTON (Fonctions Optiques pour les Technologies de l'informatiON ) - UMR 6082, F-35000 Rennes, France
Abstract

In the current context of rising popularity of perovskites as excellent materials for optoelectronics, inorganic lead halide perovskite (CsPbX3, X=Cl, Br, I) quantum dots constitute a promising platform for light emitting devices thanks to their emission spectra having extensive coverage of frequencies with narrow band as well as their photoluminescence (PL) quantum yield approaching 100% [1]. Understanding light-matter coupling and the various many-body effects is at the core of realizing the full potential of perovskite quantum dots as both classical and quantum light sources [2,3]. Many-body interaction is notably important not only for single-exciton PL [4] but also for the emission energies of trion and biexciton systems [5]. For this purpose, we utilize the Configuration Interaction (CI) approach to study the binding energies of these multiexcitonic complexes. Corroborating the experimental findings from single-dot spectroscopy, our calculations quantitatively reproduce the measured redshifts of the trion and biexciton relative to the single exciton emission from CsPbX3 quantum dots [6]. Additionally, the same theoretical method can also be employed to explain the sub-nanosecond exciton radiative lifetime in these fascinating materials [4].

[1] “Light Generation in Lead Halide Perovskite Nanocrystals: LEDs, Color Converters, Lasers, and Other Applications”, Yan, F. et al., Small 2019, https://onlinelibrary.wiley.com/doi/full/10.1002/smll.201902079

[2] “Coherent single-photon emission from colloidal lead halide perovskite quantum dots”, Utzat, H. et al., Science 2019, https://www.science.org/doi/10.1126/science.aau7392

[3] “The dark exciton ground state promotes photon-pair emission in individual perovskite nanocrystals”, Tamarat, P. et al., Nature Communications 2020, https://www.nature.com/articles/s41467-020-19740-7

[4] “Bright triplet excitons in caesium lead halide perovskites”, Becker, M. A. et al., Nature 2018, https://www.nature.com/articles/nature25147

[5] “Calculation of the biexciton shift in nanocrystals of inorganic perovskites”, Nguyen, T. P. T. et al., Phys. Rev. B 2020, https://journals.aps.org/prb/abstract/10.1103/PhysRevB.101.125424

[6] “Many-body Correlations and Bound Exciton Complexes in CsPbX3 (X=Br, Br/Cl) Quantum Dots”, Zhu, C. et al., in preparation

11:00 - 11:30
Coffee Break
Session 2B
Chair not set
11:30 - 12:00
2B-I1
Míguez, Hernán
Consejo Superior de Investigaciones Científicas (CSIC)
Photophysics of perovskite quantum dots coupled to optical cavities
Míguez, Hernán
Consejo Superior de Investigaciones Científicas (CSIC), ES

Hernán Míguez (born in Buenos Aires, Argentina, 1971) is Research Professor of the Spanish Research Council (CSIC) in the Institute of Materials Science of Seville. He studied Physics in the Universidad Autónoma de Madrid and did his PhD in the Institute of Materials Science of Madrid. After a postdoctoral stay at the University of Toronto in the group of Prof. Ozin, he returned to Spain and joined the CSIC in 2004. He leads the group of Multifunctional Optical Materials, whose activities are devoted to the development, characterization and modeling of new photonic architectures for applications in different fields, among them solar energy conversion and light emission. He has received an ERC starting grant (2012, Consolidator Modality) and the “Real Sociedad Española de Física-Fundación BBVA 2017” Prize in the modality of “Physics, Innovation and Technology”.

Authors
Hernán Míguez a
Affiliations
a, Multifunctional Optical Materials group, Institute of Materials Science of Seville, Consejo Superior de Investigaciones Científicas (CSIC) – Universidad de Sevilla, Spain, Calle Américo Vespucio, 49, Sevilla, ES
Abstract

The optical absorption and emission properties of a semiconductor or molecular materials coupled to an optical cavity differ strongly from those of the bare, uncoupled, compounds.[1] For instance, it may intensely absorb light at frequencies for which its intrinsic absorption is very low, or emit light at spectral ranges at which the uncoupled system barely shows luminescence.[2,3] The integration of lead halide perovskites into photonic structures have demonstrated the great potential this approach bears to controllably modify and enhance the photophysical properties of these semiconductors. In this talk, different ways to controllably modify the optical response of lead halide perovskites by tailoring their optical environment will be overviewed. Recent advances in the improvement of the optical quality of perovskite quantum dot solids, which has opened the door to their integration in optical cavities, will be discussed in detail, as well as their implications in the field of photovoltaics, light emitting devices and photodetection.

12:00 - 12:30
2B-I2
Klimov, Victor
Los Alamos National Laboratory, US
Realization of a Colloidal Quantum Dot Laser Diode
Klimov, Victor
Los Alamos National Laboratory, US, US

Victor I. Klimov is a Fellow of Los Alamos National Laboratory and the Director of the Center for Advanced Solar Photophysics of the U.S. Department of Energy. He received his M.S. (1978), Ph.D. (1981), and D.Sc. (1993) degrees from Moscow State University. He is a Fellow of both the American Physical Society and the Optical Society of America, and a recipient of the Humboldt Research Award. His research interests include optical spectroscopy of semiconductor and metal nanostructures, carrier relaxation processes, strongly confined multiexcitons, energy and charge transfer, and fundamental aspects of photovoltaics.

Authors
Victor Klimov a
Affiliations
a, Chemistry Division, Los Alamos National Laboratory, Los Alamos, USA, US
Abstract

Colloidal quantum dots (QDs) are attractive materials for realizing solution processable laser diodes that could benefit from the unique features of these zero-dimensional structures such as size-controlled emission wavelengths, low optical-gain thresholds, and ease of integration with photonic and electronic circuits. However, the implementation of such devices has been hampered by fast Auger recombination of gain-active multicarrier states, poor stability of QD films at high current densities, and the difficulties in obtaining net optical gain in a complex device stack wherein a thin electroluminescent QD layer is combined with optically lossy charge-transport layers. Here we resolve these challenges and achieve lasing regime in electrically pumped devices that employ compact, continuously graded QDs with strongly suppressed Auger recombination incorporated into a low-loss photonic waveguide integrated into a pulsed, high-current density light-emitting diode. These prototype colloidal QD laser diodes exhibit strong, broad-band optical gain and demonstrate low-threshold, room-temperature laser action at both the band-edge (637 nm) and the excited-state (586 nm) transitions.

12:30 - 13:00
2B-I3
Stöferle, Thilo
IBM Research – Zurich
Superfluorescence in Lead Halide Perovskite Nanocrystal Assemblies and Giant Nanocrystals
Stöferle, Thilo
IBM Research – Zurich, CH

Dr. Thilo Stöferle has been a permanent Research Staff Member at the IBM Research – Zurich Laboratory since August 2007. His current research interests are quantum simulation and quantum fluids, Bose-Einstein condensates with exciton-polaritons, integrated high Q/V cavities, nanophotonic lasers and switches. Another focus is on hybrid nanocomposite quantum materials for strong-light matter interaction and opto-electronic applications.

Authors
Etsuki Kobiyama a, Gabriele Rainò b, c, Ihor Cherniukh b, c, Yuliia Berezovska b, c, Maryna Bodnarchuk b, c, Rainer Mahrt a, Maksym Kovalenko b, c, Thilo Stöferle a
Affiliations
a, IBM Research Europe — Zurich, Säumerstrasse, 4, Rüschlikon, Switzerland
b, ETH Zurich, Laboratory of Inorganic Chemistry, Department of Chemistry & Applied Biosciences, Vladimir-Prelog-Weg, 1, Zürich, CH
c, Laboratory for Thin Films and Photovoltaics, Empa Swiss Federal Laboratories for Materials Science and Technology, 8600 Dübendorf, Suiza, Dübendorf, CH
Abstract

Cesium lead halide nanocrystals can be arranged in various kinds of superlattices by drying-mediated self-assembly using mono, binary and ternary nanocrystal compounds. Due to their small inhomogeneous emission energy spread, large oscillator strength and long dephasing times, we observe characteristic signatures of coherent, cooperative light emission, so-called superfluorescence [1]. The versatility of the material platform allows us to control the superfluorescent properties by changing the superlattice geometry [2].

Furthermore, in order to harness even more enhanced oscillator strength and narrower ensemble linewidth, we study giant nanocrystals of 50 – 200 nm size that are synthesized using ligand-assisted precipitation (LARP). With thin films of these bulk-like crystals where the excitons are clearly in the weak confinement regime, we observe signatures of superfluorescence at about an order of magnitude lower excitation power. Moreover, we investigate the emission properties in different excitation geometries and explore the cross-over to amplified spontaneous emission (ASE) at elevated temperatures.

13:00 - 13:30
2B-I4
Geiregat, Pieter
Gent University - BE
Stimulated Emission using Weakly Confined Quantum Dots
Geiregat, Pieter
Gent University - BE, BE
Authors
Ivo Tanghe a, b, c, Margarita Samoli c, Isabella Wagner d, Servet Ataberk Cayan a, c, Kai Chen d, Justin Hodgkiss d, Iwan Moreels c, Dries Van Thourhout b, Zeger Hens c, Pieter Geiregat a, c
Affiliations
a, NoLIMITS Center for Non-Linear Microscopy and Spectroscopy, Belgium, Ghent University, Gante, BE
b, Photonics Research Group, Ghent University, Belgium, Technologiepark-Zwijnaarde, 126, Gent, BE
c, Physics and Chemistry of Nanostructures, Department of Chemistry, Ghent University, Ghent, Belgium
d, School of Chemical and Physical Sciences, Victoria University of Wellington, Wellington, New Zealand, PO Box 600, Wellington, NZ
Abstract

Nanostructured semiconductors, or quantum dots (QDs), are heavily investigated for their applications in light emission such as light emitting diodes and lasers. The premise of cost-effective solution processing of such devices based on nanocrystals has recently driven research towards electrically pumped population inversion in laser diode structures. Challenges however remain to achieve net light amplification in the cavity due to a balance between limited material gains and lossy electrical contacts. Further reductions in threshold current densities, mainly limited by the non-radiative cap of ca. 1 nanosecond on the gain lifetime, are also required to achieve stable operation. Finally, color tunability is limited to the red by the gain bandwidth of the red-emitting CdSe/CdS QDs or even core/shell nanoplatelets used.

Here, we show that weakly confined charge carriers in giant CdS quantum dots display disruptive optical gain metrics that could alleviate these remaining issues. Being active in the green part of the spectrum, their properties match and even outcompeting state-of-the-art colloidal materials in the red. Material gain coefficients up to 50.000 cm-1 combined with a broad gain window of 160 nm. Also, a very promising gain lifetimes close to 3 ns is found. Invoking a model of stimulated emission based on bulk semiconductor physics, we are able to explain all of these remarkable gain metrics, yet only if a large band gap renormalization effect is invoked. Our results show that weakly confined nanomaterials are excellent gain materials, combining straightforward wet chemical synthesis and the promise of solution processability with beyond state-of-the-art gain metrics.

 
13:30 - 15:00
Lunch Break
Session 2C1
Chair not set
15:00 - 15:15
2C1-O1
Cherniukh, Ihor
Empa - Swiss Federal Laboratories for Materials Science and Technology
Superfluorescent Multicomponent Nanocrystal Superlattices from Lead Halide Perovskite Nanocubes
Cherniukh, Ihor
Empa - Swiss Federal Laboratories for Materials Science and Technology, CH
Authors
Ihor Cherniukh a, b, Gabriele Rainò a, b, Taras Sekh a, b, Thilo Stöferle c, Max Burian d, Alex Travesset e, Modestos Athanasiou f, Andreas Manoli f, Rohit John a, b, Yevhen Shynkarenko a, b, Denys Naumenko g, Heinz Amenitsch g, Grigorios Itskos f, Rolf Erni h, Rainer Mahrt c, Maryna Bodnarchuk a, b, Maksym Kovalenko a, b
Affiliations
a, Department of Chemistry and Applied Biosciences, Institute of Inorganic Chemistry, ETH Zürich, Zürich, Switzerland
b, Laboratory of Thin Films and Photovoltaics, Empa — Swiss Federal Laboratories for Materials Science and Technology, Ueberlandstrasse, 129, Dübendorf, Switzerland
c, IBM Research Europe — Zurich, Säumerstrasse, 4, Rüschlikon, Switzerland
d, Swiss Light Source, Paul Scherrer Institute, 5232 Villigen PSI, Switzerland
e, Department of Physics and Astronomy and Ames Laboratory, Iowa State University, Ames, 50011 Iowa, United States
f, Experimental Condensed Matter Physics Laboratory, Department of Physics, University of Cyprus, 1678 Nicosia, Cyprus
g, Institute of Inorganic Chemistry, Graz University of Technology, Stremayrgasse, 9, Graz, Austria
h, Electron Microscopy Center, Empa — Swiss Federal Laboratories for Materials Science and Technology, Ueberlandstrasse, 129, Dübendorf, CH
Abstract

Cesium lead halide perovskite nanocrystals, owing to high oscillator strength of bright triplet excitons, long coherence times and minimal inhomogeneous broadening of emission lines, are promising building blocks for creating superlattice structures that exhibit collective phenomena in their optical spectra. Thus far, only single-component superlattices with the simple cubic packing have been devised from these nanocrystals, which have been shown to exhibit superfluorescence – a collective emission resulting in a burst of photons with ultrafast radiative decay (ca. 20 ps) that could be tailored for use in ultrabright (quantum) light sources [1]. However, far broader structural engineerability of superlattices, required for programmable tuning of the collective emission and for building a theoretical framework can be envisioned from the recent advancements in colloidal science. We show that co-assembly of cubic and spherical steric-stabilized nanocrystals is experimentally possible and that the cubic shape of perovskite nanocrystals leads to a vastly different outcome compared to all-spherical systems. Five superlattice structures have been obtained: novel AB2, ABO3, ABO6, besides expected NaCl or common to all-sphere assemblies AlB2 superlattices [2,3]. In binary ABO3 and ABO6 superlattices, larger spherical nanocrystals occupy the A sites and smaller cubic CsPbBr3 nanocrystals reside on the B and O sites. Targeted substitution of B-site nanocubes by truncated cuboid PbS nanocrystals leads to the exclusive formation of ternary perovskite-type ABO3 superlattice. Truncated cuboid PbS NCs can occupy A-sites in binary ABO3, NaCl, and AlB2 SLs with smaller CsPbBr3 nanocubes. All synthesized superlattices exhibit a high degree of orientational ordering of the CsPbBr3 nanocubes. We also demonstrate the effect of superlattice structure on the collective optical properties.

15:15 - 15:30
2C1-O2
Rigter, Susan
Center for Nanophotonics, AMOLF, The Netherlands
Single particle optical characterization of silica nanospheres containing lead halide perovskite emitters
Rigter, Susan
Center for Nanophotonics, AMOLF, The Netherlands, NL
Authors
Susan Rigter a, b, Julia van der Burgt a, Peter Schall b, Erik Garnett a, b
Affiliations
a, Center for Nanophotonics, AMOLF, Amsterdam, The Netherlands, Science Park 104, Amsterdam, NL
b, Institute of Physics, University of Amsterdam, Science Park 904, 1098 XH Amsterdam, The Netherlands, NL
Abstract

Cesium lead halide perovskites are great candidates for lighting applications such as LEDs or screens, due to their bright photoluminescence with narrow bandwidth, originating from a tunable band gap. However, before applications can be realized, important challenges that are inherent to the materials need to be addressed. Lead halide perovskites are unstable under operation conditions - they degrade easily, for example upon contact with water, heat, or strong irradiation. Encapsulating perovskites in silica spheres stabilizes the perovskite emitters, protecting them from these influences. By controlling the shape and size of the silica, the material can be patterned and the optical properties can be tuned. In this talk, I will show the enhanced stability of perovskite emitters in silica spheres. Futhermore, I will provide an optical characterization of individual perovskite-filled silica spheres in the size range in the order of hundreds of nanometers, and methods to pattern these spheres for applications.

15:30 - 15:45
2C1-O3
Pashaei Adl, Hamid
Institute of Materials Science of the University of Valencia (ICMUV)
The thermal decoherence of superradiance in halide perovskite supercrystals
Pashaei Adl, Hamid
Institute of Materials Science of the University of Valencia (ICMUV), ES
Authors
Hamid Pashaei Adl a, Setatira Gorji a, Guillermo Muñoz Matutano a, Andrés F. Gualdrón-Reyes b, Isaac Suárez a, c, Vladimir S. Chirvony a, Iván Mora-Seró b, Juan P. Martínez-Pastor a
Affiliations
a, Instituto de Ciencia de Materiales ICMUV, Universidad de Valencia, Carrer del Catedrátic José Beltrán Martinez, 2, Paterna, ES
b, Institute of Advanced Materials INAM Universitat Jaume I, Avinguda de Vicent Sos Baynat, Castelló de la Plana, ES
c, Departamento de Ingenierıia Electronica, Escuela Tecnica Superior de Ingenierı́a, Universidad de Valencia, 46100 Burjasot, Valencia, España, Burjasot, ES
Abstract

Research into semiconductor lead halide perovskite (LHP) nanocrystals (NCs) has rapidly developed for solution-processed light emitters and photovoltaics since their hot-injection synthesis in 2015 [1, 2]. LHP NCs are currently synthesized with narrow size distributions, which naturally leads to investigations on their self-assembly capabilities. Ordered NC arrays, or supercrystals (SCs) [3], are the forms of solid-state LHP materials alternative to polycrystalline films and single crystals, which can behave very differently from their individual constituents when they interact coherently with each other. Superradiance have been recently observed for LHP SCs, identified by its spectral features [3]. In this study we show superradiance emission from CsPbBr3 supercrystal structures, with NCs lateral dimensions between 4 and 11 nm. We performed statistical analysis of the spectral characteristics, comparing our results with a theoretical model, and extract an estimation of the number of single emitters contributing to the superradiance emission. Following the photoluminiscence spectra and lifetime evolution as a function of temperature we identified two main channels for thermal decoherence of the superradiance. Our work represents an important step to understand how the supercrystal emission enhancement factor depends on thermal dephasing processes and size distribution. The future ability to manipulate N photon coherent light states with high photon homogeneity at room temperature (RT) represents a great goal for the development of new quantum technology applications [4, 5].

15:45 - 16:00
2C1-O4
Boehme, Simon
ETH Zurich, Laboratory of Inorganic Chemistry, Department of Chemistry & Applied Biosciences
Strongly Confined CsPbBr3 Perovskite Quantum Dots as Quantum Emitters and Building Blocks for Highly Ordered Rhombic Superlattices
Boehme, Simon
ETH Zurich, Laboratory of Inorganic Chemistry, Department of Chemistry & Applied Biosciences, CH
Authors
Simon Boehme a, b, Maryna Bodnarchuk a, b, Max Burian c, Federica Bertolotti d, Ihor Cherniukh a, b, Caterina Bernasconi a, b, Chenglian Zhu a, b, Heinz Amenitsch f, Denys Naumenko f, Hordii Andrusiv a, b, Nazar Semkiv a, b, Rohit Abraham John a, b, Alan Baldwin g, h, Krzystof Galkowski g, h, Norberto Masciocchi d, Samuel Stranks g, h, Gabriele Rainò a, b, Antonietta Guagliardi e, Maksym Kovalenko a, b
Affiliations
a, Institute of Inorganic Chemistry, Department of Chemistry and Applied Biosciences, ETH Zürich, 8093 Zürich, Switzerland
b, Laboratory for Thin Films and Photovoltaics, Empa, Swiss Federal Laboratories for Materials Science and Technology, 8600 Dübendorf, Switzerland
c, Swiss Light Source, Paul Scherrer Institute, 5232 Villigen, Switzerland
d, Department of Science and High Technology and To.Sca.Lab., University of Insubria, via Valleggio 11, 22100 Como, Italy, Via Valleggio, 11, Como, IT
e, Istituto di Cristallografia and To.Sca.Lab, Consiglio Nazionale delle Ricerche, Via Valleggio, 11, Como, IT
f, Institute of Inorganic Chemistry, Graz University of Technology, 8010 Graz, Austria
g, Cavendish Laboratory, University of Cambridge, JJ Thomson Avenue, Cambridge CB3 0HE, U.K.
h, Department of Chemical Engineering & Biotechnology University of Cambridge, Philippa Fawcett Drive, GB
Abstract

The success of the colloidal semiconductor quantum dot (QD) field is rooted in the precise synthetic control of QD size, shape, and composition, enabling electronically well-defined functional nanomaterials that foster fundamental science and drive diverse fields of applications. While the exploitation of the strong confinement regime has been driving commercial and scientific interest in more traditional (e.g. InP or CdSe) QDs, a thorough exploration of such a regime has still not been achieved for lead-halide perovskite QDs. Here, we overcome previous challenges of insufficient chemical stability and monodispersity of small perovskite QDs via a post-synthetic treatment employing didodecyldimethylamonium bromide ligands. The achieved high monodispersity in both size and shape enables us to prepare self-assembled QD superlattices of exceptional long-range order and uniform thickness, with an unusual rhombic packing, and with narrow-band cyan emission. Their enhanced chemical stability allows us to explore strongly confined perovskite QDs at the single-particle/single-photon level.

16:00 - 16:15
2C1-O5
Zhu, Chenglian
ETH Zürich
Highly pure single photon emission from single perovskite QDs
Zhu, Chenglian
ETH Zürich, CH
Authors
Chenglian Zhu a, b, Malwina Marczak a, b, Leon Feld a, b, Simon C. Boehme a, b, Caterina Bernasconi a, b, Anastasiia Moskalenko a, b, Ihor Cherniukh a, b, Dmitry Dirin a, b, Maryna I. Bodnarchuk a, b, Maksym V. Kovalenko a, b, Gabriele Raino a, b
Affiliations
a, Institute of Inorganic Chemistry, Department of Chemistry and Applied Biosciences, ETH Zürich, CH-8093 Zürich, Switzerland
b, Laboratory for Thin Films and Photovoltaics, Empa Swiss Federal Laboratories for Materials Science and Technology, 8600 Dübendorf, Suiza, Dübendorf, CH
Abstract

Attaining pure single-photon emission is key for many quantum technologies,[1] from optical quantum computing[2] to quantum key distribution[3] and quantum imaging.[4] The past 20 years have seen the development of several solid-state quantum emitters, but most of them require highly sophisticated techniques (e.g., ultra-high vacuum growth methods and cryostats for low-temperature operation). The system complexity may be significantly reduced by employing quantum emitters capable of working at room temperature. Lead-halide perovskite APbX3 (A=Cs or organic cation; X=Cl, Br, I) quantum dots (QDs) are one of the desired materials, of particular interest due to their low-cost synthesis, solution processability, tunability of the emission wavelength via size and composition, narrow-band emission, short radiative lifetime (~ns at RT) as well as high photoluminescence quantum yield (QY).[5,6] Here, we present a systematic study across ∼ 170 photostable single CsPbX3 (X: Br and I) colloidal QDs of different sizes and compositions, unveiling that increasing quantum confinement is an effective strategy for maximizing single-photon purity due to the suppressed biexciton quantum yield. Leveraging the latter, we achieve 98% single-photon purity (g(2)(0) as low as 2%) from a cavity-free, non-resonantly excited single 6.6 nm CsPbI3 QDs, showcasing the great potential of CsPbX3 QDs as room-temperature highly pure single-photon sources for quantum technologies.

16:15 - 16:30
2C1-O6
Kahmann, Simon
Luminescence of 2D Perovskites – on Trapping and Self-Trapping
Kahmann, Simon
Authors
Simon Kahmann a, b
Affiliations
a, Cavendish Laboratory University of Cambridge, JJ Thomson Avenue, GB
b, Department of Chemical Engineering and Biotechnology, University of Cambridge, Philippa Fawcett Drive, GB
Abstract

Although studied since the 1980’s, research on two-dimensional metal halide perovskites (2D HaPs) has only recently exploded in the shadow of their 3D counterparts. Now, these compounds are studied for improving both the performance and the stability of solar cells, as well as for use in light-emitting devices, scintillators, gas detectors, and many more applications.

As a key difference compared to 3D HaPs, their two-dimensional nature leads charge carriers to form strongly bound excitons, making them excellent testbeds for exciton physics in confined systems, and for applications that require bright luminescence.

Curiously, some of these compounds exhibit narrow emission lines from the band edge (often with a complex sub-structure), whereas others give rise to broad and strongly red-shifted luminescence – or a combination of both.

In my talk, I shall address the different concepts invoked to explain the luminescence of 2D HaPs, how different propositions can be distinguished experimentally, and how variation of the constituent metal and halides affect the overall optoelectronics of this family of materials. A combination of photoluminescence spectroscopy and density functional theory computation is used to reveal the intricate origin of broad emission bands in a family of <100> oriented compounds.

16:30 - 16:45
2C1-O7
Dirin, Dmitry
Swiss Federal Institute of Technology ETH Zurich
Intrinsic formamidinium tin iodide nanocrystals by suppressing the Sn(IV) impurities
Dirin, Dmitry
Swiss Federal Institute of Technology ETH Zurich, CH
Authors
Dmitry Dirin a, b, Anna Vivani c, Marios Zacharias d, Ihor Cherniukh a, b, Sergii Yakunin a, b, Federica Bertolotti c, Marcel Aebli a, b, Richard Schaller e, f, Norberto Masciocchi c, Antonietta Guagliardi g, Laurent Pedesseau d, Jacky Even d, Maksym Kovalenko a, b, Maryna Bodnarchuk a, b
Affiliations
a, Department of Chemistry and Applied Biosciences, ETHZ
b, Laboratory of Thin Films and Photovoltaics, Empa — Swiss Federal Laboratories for Materials Science and Technology, Ueberlandstrasse, 129, Dübendorf, Switzerland
c, Dipartimento di Scienza e Alta Tecnologia and To.Sca.Lab, Università dell’Insubria, via Valleggio 11, I-22100 Como, Italy
d, Univ Rennes, INSA Rennes, CNRS, Institut FOTON - UMR6082, France, FR
e, Center for Nanoscale Materials, Argonne National Laboratory, USA., Argonne Dr, Woodridge, US
f, Department of Chemistry, Northwestern University, Evanston, USA, Sheridan Road, 2145, Evanston, US
g, Istituto di Cristallografia and To.Sca.Lab, Consiglio Nazionale delle Ricerche, via Valleggio 11, I-22100 Como, Italy
Abstract

Lead halide perovskites successfully advance towards applications in solar cells, light-emitting devices, and high-energy radiation detectors. Recent progress in understanding their uniqueness highlights the role of optoelectronic tolerance to intrinsic defects, particularly long diffusion lengths of carriers, and highly dynamic 3d inorganic framework. This picture indicates that finding an analogous material among non-group-14 metal halides can be very challenging, if possible at all. On the other hand, Sn (II) iodide perovskites exhibit comparably good performance in photovoltaics when synthesized with a low number of trap states. The main challenge with this material originates from the easiness of the trap states generation, which are typically ascribed to the oxidation of Sn(II) to Sn(IV). In this work, we describe the synthesis of colloidal monodisperse FASnI3 NCs, wherein thorough care on the purity of precursors and redox chemistry reduces the concentration of Sn(IV) to an insignificant level, to probe the intrinsic structural and optical properties of these NCs.

17:00 - 19:00
Poster Session
 
Wed Oct 05 2022
09:55 - 10:00
nanoGe Introduction
Session 3A
Chair not set
10:00 - 10:30
3A-I1
Konstantatos, Gerasimos
ICFO-Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology
Infrared Colloidal Quantum Optoelectronics: LEDs and Lasers
Konstantatos, Gerasimos
ICFO-Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, ES
Gerasimos Konstantatos received the Diploma from the University of Patras, Patras, Greece, in 2001 and the M.A.Sc. and Ph.D. degrees from University of Toronto, Toronto, ON, Canada, in 2004 and 2008, respectively, all in electrical and computer engineering.He is currently a Group Leader with ICFO - the Institute of Photonic Sciences, Castelldefels, Barcelona, Spain. His work has been published in over 25 journal articles, 7 of them in Nature-family journals, in the field of colloidal quantum dot optoelectonics. He is also an inventor of 5 granted patents licensed to Invisage Technologies and a recipient of the TR35 Spain 2012 award for his contributions on colloidal quantum dot photodetectors. His current research interests lie in the field of solution processed functional nanomaterials for solar cell and optical sensor applications.
Authors
Gerasimos Konstantatos a
Affiliations
a, ICFO - Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, 08860 Sitges, Barcelona, España, Sitges, ES
Abstract

Solution Processed CMOS compatible Infrared Optoelectronics is a key enabling technology to revolutionize consumer electronic markets offering unprecedented opportunities for low-cost food quality inspection, environmental monitoring, 3D imaging, automotive safety and night vision applications just to name a few. Recent progress in CMOS compatible CQD photodetectors have addressed the InGaAs image sensor challenge and the next step would be the development of the correspondingly low-cost tunable light sources. In this talk, I will be presenting recent results from my lab at ICFO on highly performant infrared CQD LEDs and downconverting light emitters.

I will present our device architecture approach that allowed us to achieve very high PLQY in conductive solid state QD films that when implemented in a LED stack led to 8% EQE [1]. I will then discuss the optimization of the matrix supply dots that improved charge balance and allowed to reach 8% EQE at high radiance along with a stark improvement in operational stability [2]. I will then elaborate on fine-tuning the energetic potential landscape in the matrix which taken together with optimized optical out-coupling schemes reached a QE of 18% at 1550 nm. The possibility to tune the light spectrum of such QD films by stacking layers of QDs with different bandgaps offers exquisite control over the emission spectrum offering the opportunity to develop solid-state thin film broadband emitters in the SWIR, either optically or electrically excited with implications in SWIR spectroscopy [3].

The second part of my talk will discuss recent progress on infrared CQD lasers comprising doped PbS CQDs integrated in a DFB cavity [4]. Besides this I will present our approach of elongating Auger lifetime by  engineering QD solids at the supra-nanocrystalline level offering lasers with improved optical linewidths, reduced thresholds and drastically improved stability [5].

 

References:

[1] High-efficiency colloidal quantum dot infrared light-emitting diodes via engineering at the supra-nanocrystalline level, Nature nanotechnology 14 (1), 72-79, 2019

[2] Highly Efficient, Bright, and Stable Colloidal Quantum Dot Short‐Wave Infrared Light‐Emitting Diodes, Advanced Functional Materials 30 (39), 2004445, 2020

[3] Solid‐State Thin‐Film Broadband Short‐Wave Infrared Light Emitters, Advanced Materials 32 (45), 2003830, 2020

[4] Solution-processed PbS quantum dot infrared laser with room-temperature tunable emission in the optical telecommunications window, Nature Photonics 15 (10), 738-742, 2021

[5] Low‐Threshold, Highly Stable Colloidal Quantum Dot Short‐Wave Infrared Laser enabled by Suppression of Trap‐Assisted Auger Recombination, Advanced Materials 34 (3), 2107532, 2022

10:30 - 11:00
3A-I2
Bradley, Donal
KAUST
Microstructure Control of Polymer Electronic and Optical Properties: Polyfluorene Conformation and Orientation for Optimized Cavity Exciton-Photon Coupling and Light Emission
Bradley, Donal
KAUST, SA
Authors
Donal Bradley b
Affiliations
a, Physical Science and Engineering Division, KAUST, Thuwal St, Dhahran, SA
b, Department of Physics, University of Oxford, Clarendon Laboratory, Oxford OX1 3PU, U.K.
Abstract

The many conformations of glassy conjugated polymer chains define the characteristic ensemble broadening of their optical and electrical density of states functions, with adjustments in microstructure typically leading to relatively modest changes in distribution peak energy and width. This allows little prospect for the practical use of conformation control since the resulting changes in properties are insufficiently stark. However, in the circumstance that the distribution of conformational energies is not simply Gaussian but rather includes a distinct and readily generated low-energy subspecies it becomes possible to use conformation as a vector for function control. This is the situation for ß-phase formation in poly(9,9-dioctylfluorene) (PFO) and related materials, where the resulting ß-phase segments contribute a clearly resolved, red shifted peak that superposes on the co-existing glassy phase ensemble. In essence, this situation parallels the opportunities afforded by configuration control using photoisomer pairs such as the cis and trans forms of azobenzene molecules and represents a novel molecular approach to metamaterials creation. ß-phase formation modulates refractive index, emission colour, charge carrier mobility and several aspects of photophysics which, combined with spatial patterning, then allows the fabrication of novel structures and the enhancement of device performance.

Optical environment, namely whether the polymer film emits into free-space or is confined within an optical structure that defines the available modes, also provides a means to tune optoelectronic properties. Of particular interest is the situation in which the polymer exciton dipole moment and cavity confinement are large enough that hybridisation occurs to form exciton-polariton states. Two main regimes arise, strong- and ultrastrong-coupling (with less-explored variants deep-strong and very-strong coupling) and these regimes offer novel application possibilities in relation to emission characteristics. Additional control of the polymer chain conformation or its alignment within such a microcavity then allows subtle control over the polariton physics, yielding desirable emission characteristics in terms of colour saturation and angular dispersion and generating record coupling strengths for which new physics can be explored.

Specific examples will be presented in this talk for PFO and fluorene-based copolymers, including poly((9,9-dioctylfluorene)x-co-(phenylenediamine)y), poly(9,9-dioctylfluorene-co-benzothiadiazole (F8BT) and poly(9,9-dihexylfluorene-co-bithiophene (F6T2), also cases where thermal control can be used to tune conformation (e.g.poly[4-(octyloxy)-9,9-diphenylfluorene]-co-[5-(octyloxy)-9,9-diphenylfluorene] (PODPF)).

11:00 - 11:30
Coffee Break
Session 3B
Chair not set
11:30 - 12:00
3B-I1
Demir, Hilmi Volkan
Semiconductor Nanocrystal Optoelectronics for Lighting and Displays
Demir, Hilmi Volkan
Authors
Hilmi Volkan Demir b
Affiliations
a, NTU Singapore – Nanyang Technological University School of Electrical and Electronic Engineering, School of Physical and Mathematical Sciences, School of Materials Science and Engineering, Singapore
b, Bilkent University Department of Electrical and Electronics Engineering, Department of Physics, UNAM--Institute of Materials Science and Nanotechnology, Ankara, Turkey
Abstract

Semiconductor nanocrystals have attracted great interest in quality lighting and displays in the last decade. In this talk, we will introduce semiconductor nanocrystal optoelectronics with most recent examples of the photonic structures and optoelectronic devices employing atomically‑flat, tightly‑confined, quasi‑2‑dimensional colloidal quantum wells (CQWs), also popularly nick‑named ‘nanoplatelets’. Among various extraordinary features of theirs, we will present that these CQWs enable record high optical gain coefficients [1] and can achieve gain thresholds at the level of sub‑single exciton population in the ensemble per CQW on the average [2], empowered by carefully engineering their heterostructures [3,4]. Also, we will show record high‑efficiency colloidal LEDs using heterostructured CQWs employed as the electrically‑driven active emitter layer [5] and record low-threshold solution lasers using the same CQWs employed as the optically‑pumped fluidic gain medium [6]. Given their current accelerating progress, these solution‑processed quantum well materials hold great promise to challenge their epitaxial thin‑film counterparts in semiconductor optoelectronics in the near future.

12:00 - 12:30
3B-I2
Gao, Feng
Linkoping University
The effect of molecular additives on perovskite light-emitting diodes
Gao, Feng
Linkoping University, SE
Authors
Feng Gao a
Affiliations
a, Department of Physics Chemistry and Biology Linköping University, 83, 581, SE
Abstract

Metal halide perovskites have shown promising optoelectronic properties suitable for light-emitting applications. The development of perovskite light-emitting diodes (PeLEDs) has progressed rapidly over the past several years, and molecular additives have played an important role in these advances. By rational design of these molecular additives, we can significantly enhance the interaction with defects sites and minimize non-radiative recombination losses. In addition, we also demonstrate that the molecular additives can manipulate the perovskite crystallization and help to enhance the radiative recombination. As such, we have been able to demonstrate highly efficient near infrared perovskite LEDs with external quantum efficiencies over 20% and also excellent operational stability. In addition, we find that our devices can also work efficiently in an emitting/detector switchable mode, with tens-megahertz speed for both functions. We further demonstrate the potential of the dual-functional diode for biomedicine diagnosis applications (as a monolithic heart pulse sensor) and for inter- and intra-chip bidirectional optical communications.

12:30 - 13:00
3B-I3
Mohammed, Omar
King Abdullah University of Science and Technology (KAUST) - Saudi Arabia
High-performance Silver and Copper Halide X-ray Imaging Scintillators
Mohammed, Omar
King Abdullah University of Science and Technology (KAUST) - Saudi Arabia, SA
Authors
Omar Mohammed a
Affiliations
a, King Abdullah University of Science and Technology (KAUST), SA
Abstract

Scintillators are critical for high-energy radiation detection across a wide array of potential applications, from medical radiography and safety inspections all the way to space exploration. However, constrained by their current shortcomings, including high-temperature and complex fabrication, high cost, and inherent brittleness and fragility among thick films and bulk crystals, traditional scintillators are finding it difficult to meet the rising demand for cost-effective, eco-friendly, and flexible X-ray detection. Here, we describe the development of highly efficient and flexible X-ray scintillators based on films of Cu-doped Cs2AgI3, which exhibit ultrahigh X-ray sensitivity. The materials exhibit a high scintillation light yield of up to 82900 photons/MeV and a low detection limit of 77.8 nGyair/s, which is approximately 70 times lower than the dosage for a standard medical examination. Moreover, richly detailed X-ray images of biological tissue and electronic components with a high spatial resolution of 16.2 lp/mm were obtained using flexible large-area solution-processed scintillation screens. These findings demonstrate that Cu-doped Cs2AgI3 films can serve as extraordinary scintillation screens for high-performance X-ray imaging devices.

13:00 - 13:30
3B-I4
Strtatakis, Emmanuel
Fundació Scito
Abstract Prof. Emmanuel Strtatakis
Strtatakis, Emmanuel
Fundació Scito, ES
Authors
Emmanuel Strtatakis a
Affiliations
a, Fundació Scito, Carrer de Campoamor, 73, València, ES
Abstract

Abstract Prof. Emmanuel StrtatakisAbstract Prof. Emmanuel StrtatakisAbstract Prof. Emmanuel StrtatakisAbstract Prof. Emmanuel StrtatakisAbstract Prof. Emmanuel StrtatakisAbstract Prof. Emmanuel StrtatakisAbstract Prof. Emmanuel StrtatakisAbstract Prof. Emmanuel StrtatakisAbstract Prof. Emmanuel StrtatakisAbstract Prof. Emmanuel StrtatakisAbstract Prof. Emmanuel StrtatakisAbstract Prof. Emmanuel StrtatakisAbstract Prof. Emmanuel StrtatakisAbstract Prof. Emmanuel StrtatakisAbstract Prof. Emmanuel StrtatakisAbstract Prof. Emmanuel StrtatakisAbstract Prof. Emmanuel StrtatakisAbstract Prof. Emmanuel StrtatakisAbstract Prof. Emmanuel StrtatakisAbstract Prof. Emmanuel StrtatakisAbstract Prof. Emmanuel StrtatakisAbstract Prof. Emmanuel StrtatakisAbstract Prof. Emmanuel StrtatakisAbstract Prof. Emmanuel StrtatakisAbstract Prof. Emmanuel StrtatakisAbstract Prof. Emmanuel StrtatakisAbstract Prof. Emmanuel StrtatakisAbstract Prof. Emmanuel StrtatakisAbstract Prof. Emmanuel StrtatakisAbstract Prof. Emmanuel StrtatakisAbstract Prof. Emmanuel StrtatakisAbstract Prof. Emmanuel StrtatakisAbstract Prof. Emmanuel StrtatakisAbstract Prof. Emmanuel StrtatakisAbstract Prof. Emmanuel StrtatakisAbstract Prof. Emmanuel StrtatakisAbstract Prof. Emmanuel StrtatakisAbstract Prof. Emmanuel StrtatakisAbstract Prof. Emmanuel StrtatakisAbstract Prof. Emmanuel StrtatakisAbstract Prof. Emmanuel StrtatakisAbstract Prof. Emmanuel StrtatakisAbstract Prof. Emmanuel StrtatakisAbstract Prof. Emmanuel StrtatakisAbstract Prof. Emmanuel StrtatakisAbstract Prof. Emmanuel StrtatakisAbstract Prof. Emmanuel StrtatakisAbstract Prof. Emmanuel StrtatakisAbstract Prof. Emmanuel StrtatakisAbstract Prof. Emmanuel StrtatakisAbstract Prof. Emmanuel StrtatakisAbstract Prof. Emmanuel StrtatakisAbstract Prof. Emmanuel Strtatakis

13:30 - 15:00
Lunch Break
Session 3C1
Chair not set
15:00 - 15:15
3C1-O1
Athanasiou, Modestos
Experimental Condensed Matter Physics Lab, Department of Physics, University of Cyprus
Flexible, Free Standing Polymer Membranes Sensitized by CsPbX3 Nanocrystals as Gain Media for Low Threshold, Multi-Color Light Amplification
Athanasiou, Modestos
Experimental Condensed Matter Physics Lab, Department of Physics, University of Cyprus, CY
Authors
Modestos Athanasiou a, Andreas Manoli a, Paris Papagiorgis a, Kyriacos Georgiou b, Yulia Berezovska c, Andreas Othonos b, Maryna Bodnarchuk c, Maksym Kovalenko d, Grigorios Itksos a
Affiliations
a, Experimental Condensed Matter Physics Laboratory, Department of Physics, University of Cyprus, 1678 Nicosia, Cyprus
b, Laboratory of Ultrafast Science, Department of Physics University of Cyprus, Nicosia, CY
c, Laboratory for Thin Films and Photovoltaics, Empa Swiss Federal Laboratories for Materials Science and Technology, 8600 Dübendorf, Suiza, Dübendorf, CH
d, Institute of Inorganic Chemistry, Department of Chemistry and Applied Biosciences, ETH Zürich, 8093 Zürich, Switzerland
Abstract

Lead halide perovskite nanocrystals (LHP NCs) are attractive for optically-pumped, solution-processed lasers in the visible, owing to their wide spectral tunability, their outstanding optical gain properties and the suppressed non-radiative recombination losses stemming from their defect-tolerant nature. In this work, we demonstrate flexible waveguides combining the transparent, bioplastic, polymer cellulose acetate (CA) with green-emitting CsPbBr3 or red-emitting CsPb(Br,I)3 NCs in solution-processed architectures based on polymer-NC multilayers deposited on CA micro-slabs.

Experiments and simulations indicate that the employment of the thin, free-standing CA membranes results in confined electrical fields, enhanced by two orders of magnitude compared to identical multilayer stacks deposited on conventional, thick and rigid quartz substrates. As a result, the polymer structures exhibit improved amplified spontaneous emission (ASE) characteristics under nanosecond excitation, with ASE thresholds down to 95 μJ cm-2 in the green and 70 μJ cm-2 in the red and high net modal gain up to 450 cm-1 and 630 cm-1, respectively. The optimized gain properties are accompanied by a notable improvement of the ASE operational stability due to the low thermal resistance of the substrate-less membranes and the intimate thermal contact between the polymer and the NCs. Their application potential is further highlighted by the membrane ability to sustain dual-color ASE in the green and red through excitation by a single UV source and the activation of underwater stimulated emission

Lead halide perovskite nanocrystals (LHP NCs) are attractive for optically-pumped, solution-processed lasers in the visible, owing to their wide spectral tunability, their outstanding optical gain properties and the suppressed non-radiative recombination losses stemming from their defect-tolerant nature. In this work, we demonstrate flexible waveguides combining the transparent, bioplastic, polymer cellulose acetate (CA) with green-emitting CsPbBr3 or red-emitting CsPb(Br,I)3 NCs in solution-processed architectures based on polymer-NC multilayers deposited on CA micro-slabs.

Experiments and simulations indicate that the employment of the thin, free-standing CA membranes results in confined electrical fields, enhanced by two orders of magnitude compared to identical multilayer stacks deposited on conventional, thick and rigid quartz substrates. As a result, the polymer structures exhibit improved amplified spontaneous emission (ASE) characteristics under nanosecond excitation, with ASE thresholds down to 95 μJ cm-2 in the green and 70 μJ cm-2 in the red and high net modal gain up to 450 cm-1 and 630 cm-1, respectively. The optimized gain properties are accompanied by a notable improvement of the ASE operational stability due to the low thermal resistance of the substrate-less membranes and the intimate thermal contact between the polymer and the NCs. Their application potential is further highlighted by the membrane ability to sustain dual-color ASE in the green and red through excitation by a single UV source and the activation of underwater stimulated emission

15:15 - 15:30
3C1-O2
Martínez Pastor, Juan P.
Universitat de València (UV), Spain
Photon Recycling in planar waveguides integrating low-dimensional perovskite semiconductors
Martínez Pastor, Juan P.
Universitat de València (UV), Spain, ES

Juan P. Martínez-Pastor, Full Prof. at the University of Valencia. PhD in Physics, 1990. Three years of postdoctoral experience at the European Laboratory of Non-Linear Spectroscopy (Florence, Italy) and at the École Normale Supérieure (Paris, France). Prof. Martínez-Pastor is expert in Semiconductor Physics, particularly optical properties and exciton recombination dynamics in quantum wells, wires and dots based on III-V semiconductors and other compounds since 1990. This research line continues nowadays focused on quantum light produced by quantum dot semiconductors and its management for quantum communications. After 2006 he has leaded/co-leaded several research lines in nanoscience and nanotechnology regarding the development of several types of nanomaterials (metal and quantum dots, multi-functional nanocomposites) and applications to photonics and plasmonics. In the last three years, he focuses his research in optical properties, exciton recombination dynamics and applications in photonics of two-dimensional semiconductors and metal halide perovskites. He has supervised 16 PhD theses and is author/co-author of 220 peer-reviewed publications, other than seven patents and promotor of a spin-off company.

Authors
Juan P. Martínez Pastor a, Hamid Pashaei Adl a, Juan Navarro Arenas a, Jesús Sánchez-Díaz b, Rafael S. Sánchez b, Andrés F. Gualdrón Reyes b, Juan Bisquert b, Iván Mora Seró b, Isaac Suárez c
Affiliations
a, Institut de Ciencia dels Materials (ICMUV), Universitat de València, c Catedratic Beltran 2, 46980 Paterna, Valencia, Spain
b, Institute of Advanced Materials (INAM), Universitat Jaume I, Avinguda de Vicent Sos Baynat, Castelló de la Plana, ES
c, Escuela Técnica Superior de Ingeniería, Universidad de Valencia, Valencia 46100, Spain, Avenida de la Universidad s/n, Burjassot, ES
Abstract

Photon recycling (PR) is an outstanding physical process that consists on the reabsorption and re-emission of radiatively emitted photons in semiconductor thin films. These multiple reabsorption/reemission cycles can significantly increase the photon and carrier densities in solar cells or light-emitting sources, hence it has important implications towards the enhancement of the performances of these devices (Ansari-Rad & Bisquert, 2018). In this context, perovskite materials present optimum characteristics to favor the PR effect (Pazos-Outón et al., 2016); namely large absorption coefficient and sharp edge, together with relatively narrow photoluminescence (PL) spectra, short Stokes-shift (SS) between exciton PL and absorption, and high PL quantum yield. In this scenario, we have recently demonstrated a record of PR effect by integrating a close packed layer of CsPbBr3 NCs on a planar waveguide configuration (PMMA/perovskite/PMMA). The advantage of this geometry, compared to the case of a standard thin film, is the high confinement of the electromagnetic field at the semiconductor and, with it, the important enhancement of the exciton absorption and emission processes. As a consequence, this photonic device extended the PR effect over mm-distances, as revealed by the SS of the collected PL up to 32.5 meV and the increase of the decay time from 3 to 9 ns (see figure). In this talk we will compare and discuss the PR effect observed in optical waveguides incorporating films of CsPbBr3 nanocrystals (3D carrier confinement) and PEA2SnI4 (1D carrier confinement). The PR effect was appropriately characterized by a frequency-domain fluorescence spectroscopy technique, and modelled with rate equations and stochastic Monte Carlo simulations in the case of perovskite nanocrystals (J. Navarro et al., 2020), where carrier diffusion is absent. In the case of the 2D tin-perovskite, we evaluate the effect of diffusion in the waveguided PR mechanism. Our results provide new insights towards a deeper understanding of the PR phenomenon, whose significance could be extended for designing and optimizing the PR effect in solar cells and light-emitting devices.

 

15:30 - 15:45
3C1-O3
Chirvony, Vladimir
Universitat de València (UV), Spain
Spectrally Stable High-Q and Low Threshold Random Lasing in Polycrystalline Films of FASnI3 Halide Perovskite
Chirvony, Vladimir
Universitat de València (UV), Spain, ES
Authors
Vladimir Chirvony a, Isaac Suárez b, Jesus Sánchez-Diaz c, Rafael Sánchez c, Jesús Rodríguez-Romero d, Iván Mora-Seró c, Juan Martínez-Pastor a
Affiliations
a, Instituto de Ciencia de los Materiales, Universidad de Valencia, Valencia 46980, Spain
b, Escuela Técnica Superior de Ingeniería, Universidad de Valencia, Valencia 46100, Spain, Avenida de la Universidad s/n, Burjassot, ES
c, Institute of Advanced Materials (INAM), Universitat Jaume I, Castelló de la Plana, Castelló 12006, Spain
d, Facultad de Química, Universidad Nacional Autónoma de México, Coyoacán, Ciudad de México 04510, Mexico
Abstract

The potential applicability of random lasers is largely limited because of chaotic fluctuations of spectral positions of lasing modes. In the present work we disclosed that spectrally stable narrow random lasing (RL) lines with quality factor Q as high as Q ≈ 10^4 at 20 K and the Amplified Spontaneous Emission (ASE) threshold as low as 2 microJ/cm2 are generated in thin polycrystalline films of formamidinium tin triiodide (FASnI3) perovskite chemically stabilized against Sn2+ to Sn4+ oxidation. The spectral positions of the RL lines are stable not only under unchanged excitation fluence, but also when the fluence alters by more than one order of magnitude. We found that different mechanisms are responsible for the formation of broad ASE contour and narrow RL lines and that ASE can be essentially suppressed by means of a decrease of the excitation spot linear size from ≈ 400 to ≈ 100 micrometers. Statistical analysis of RL line spacing suggests that a set of strongly localized modes is responsible for the observed set of narrow RL lines. We suggest also that high refractive index as well as high density of grain package are the main factors which determine the RL spectral stability and high Q and differ FASnI3 perovskite polycrystalline films from their widely studied Pb-based perovskite counterparts where chaotic RL is observed.

15:45 - 16:00
3C1-O4
Shaek, Saar
Technion - Israel Institute of Technology
Why the Case of Self Trapped Excitons is so Different for Bi doping and Sb doping of Lead-Free Halide Double Perovskites
Shaek, Saar
Technion - Israel Institute of Technology, IL
Authors
Saar Shaek a, Yehonadav Bekenstein a
Affiliations
a, Department of Materials Science and Engineering, Technion – Israel Institute of Technology, Haifa, 3200003, Israel
Abstract

Lead halide perovskites are intriguing candidates for the display industry. Lead-free perovskites are of interest due to their nontoxicity. However, engineering their optical properties is still in its infancy.

Controlling the optical properties is a fundamental goal for improving device performances. Here, we focus on tuning the optical properties of silver-based double perovskite nanocrystals via two iso-valent dopants, Bi and Sb. The PL quantum yield of the intrinsic Cs2Ag1-yNayInCl6 perovskite increases dramatically upon doping. The two dopants affect the optical properties differently. We hypothesize that this effect is related to exciton-phonon coupling in double perovskites. The mechanism allows broad white light emission wavelength and no overlap between the absorption and the emission, which is compatible with luminescent solar concentrators. Luminescent solar concentrators are light-harvesting devices that redirect the light to a photovoltaic cell. We test the exciton-phonon coupling through absorption and photoluminescence measurements using the Haung-Rhys factor calculation. Using colloidal open-air synthesis, we control the perovskite matrix and the doping concentration. We can differentiate between contributions from Bi and Sb levels marking different electronic considerations. This exemplifies the essence of the resulting practices for tuning and optimizing the optical properties of double perovskite nanocrystals.

16:00 - 16:15
3C1-O5
Yuan, Zhongcheng
University Oxford
Interface-assisted cesium-formamidinium cation exchange enables high-performance perovskite light-emitting diodes with tuneable near-infrared emissions
Yuan, Zhongcheng
University Oxford, GB
Authors
Zhongcheng Yuan a, b, Zhangjun Hu a, Ingemar Persson a, Chuanfei Wang a, Xianjie Liu a, Chaoyang Kuang a, Weidong Xu a, Sai Bai a, Feng Gao a
Affiliations
a, Department of Physics, Chemistry and Biology (IFM), Linköping University, Linköping, SE-58183, Sweden
b, Department of Physics University of Oxford Clarendon Laboratory, Oxford OX1 3PU, Reino Unido, GB
Abstract

Achieving high-quality cesium-formamidinium lead iodide (CsxFA1-xPbI3) perovskites with widely tuneable bandgaps
is highly desired for their optoelectronic applications yet remains a challenge because of the different phase transition
behaviour of FAPbI3 and CsPbI3 perovskite during film depositions.1,2 Herein, by utilizing an alkaline-interface-assisted
cation-exchange method, we fabricate a set of highly emissive CsxFA1-xPbI3 perovskite films with fine-tuning Cs-FA
alloying ratio for emission-tuneable near-infrared light-emitting diodes (NIR-LEDs). We reveal that the deprotonation
of FA+ cations and the formation of hydrogen-bonded gels consisting of CsI and FA facilitated by zinc oxide underneath
effectively removes the Cs-FA ion-exchange barrier, promoting the formation of phase-pure CsxFA1-xPbI3 films with
emission filling the gap between that of pure Cs- and FA-based perovskites.3 The obtained NIR-LEDs with narrow
electroluminescence peaking from 715 to 780 nm simultaneously demonstrate high peak external quantum efficiencies
of over 15%, maximum radiances exceeding 300 W sr-1 m-2, and high power conversion efficiencies above 10 % at 100
mA cm-2, representing the best-performing devices based on solution-processed wavelength-tuneable NIR emitters in
the similar region4.

1 Li, Z., et.al. Chem. Mater. 28, 284-292 (2016)
2 Lee, J.-W., et.al. Adv. Energy Mater. 5, 1501310 (2015)
3 Z, Yuan., et.al. Nat. Commun 10, 2818 (2019)
4 Z, Yuan., et.al. In revision.

16:15 - 16:30
3C1-O6
Schröder, Vincent R. F.
Helmholtz Zentrum Berlin für Materialien und Energie
Combinatorial colour printing of metal halide perovskites
Schröder, Vincent R. F.
Helmholtz Zentrum Berlin für Materialien und Energie, DE
Authors
Vincent R. F. Schröder a, b, Felix Hermerschmidt b, Hampus Näsström c, Florian Mathies c, Eva L. Unger c, d, Emil J. W. List-Kratochvil a, b
Affiliations
a, Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, Hahn-Meitner-Platz 1, 14109 Berlin, Germany.
b, Humboldt-Universität zu Berlin, Institut für Physik, Institut für Chemie, IRIS Adlershof,, Zum Großen Windkanal, 2, Berlin, DE
c, Young Investigator Group Hybrid Materials Formation and Scaling, Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, Albert-Einstein-Straße, 15, Berlin, DE
d, Chemical Physics and NanoLund, Lund University, PO Box 124, 22100 Lund, Sweden
Abstract

The development of metal-halide perovskite-based optoelectronic devices continues to reach new record efficiencies and operation lifetimes. While most of the device fabrication is still done by spin-coating of a previous-prepared precursor solution, inkjet printing was already used for the fabrication of solar cells and light emitting diodes.[1] Beyond scalable, high‑throughput and large‑area coating, inkjet printing also enables variation of the deposited material during processing.
Using combinatorial inkjet printing, multiple precursor inks can be deposited in a single printing step to achieve compositionally mixed perovskite thin films and gradients. The composition of the resulting film can thereby be precisely controlled by adjusting the droplet ratio of both inks during the printing process. A pre-made image, fed into the printer, allows thereby to produce arbitrary patterns of metal halide perovskite film with compositional gradients.[2] Beyond being a powerful tool for high-throughput material discovery, we demonstrate the direct use of combinatorial inkjet printing for device fabrication. Utilizing methylammonium lead iodide, bromide and chloride inks, we fabricated a series of MAPb(IxBr1-x)3 and MAPb(BrxCl1-x)3 thin films. The well-known gradient of the bandgap energy in this series allowed us to produce a series of wavelength-selective photodetectors, covering the whole spectrum of visible light from 1.6 eV (MAPbI3) to 3.0 eV (MAPbCl3) in a single printing step.[3]

Session 3C2
Chair not set
15:00 - 15:15
3C2-O1
Christodoulou, Sotirios
University of Cyprus
Near-Infrared gain and stimulated emission from green colloidal InAs/ZnSe quantum dots
Christodoulou, Sotirios
University of Cyprus, CY
Authors
Sotirios Christodoulou a, Nefeli Polycarpou a, Eleftheria Charalampous a, Dongxu Zhu c, Andreas Othonos b, Luca Di Trizio c, Liberato Manna c
Affiliations
a, Inorganic Nanocrystals Laboratory, Department of Chemistry, University of Cyprus, Nicosia, CY
b, Laboratory of Ultrafast Science, Department of Physics University of Cyprus, Nicosia, CY
c, Nanochemistry Department, Istituto Italiano di Tecnologia, via Morego 30, 16163 Genova, Italy
Abstract

Over the last two decades, CdSe-based colloidal quantum dots (CQDs) and most recently perovskite nanocrystals have been under the spotlight for lasing application as exhibit excellent optoelectronic properties such as high photoluminescence quantum yield (PLQY), optical stability and wide emission tunability. Already, CQD technology has delivered ultra-low lasing and stimulated emission thresholds even with continuous-wave excitation (CW).1 Nevertheless, the research has centred on UV-Vis while very few examples have been shown in the low energy part of the electromagnetic spectrum.

On the other hand, light sources (lasers) in infrared are still the last piece missing for the realization of silicon Photonics (CMOS), while photodetectors and modulators on Si have been already demonstrated. In the last couple of years, toxic mercury2 and lead-based colloidal quantum dots have shown amplified stimulated emission3 and lasing4 in shortwave infrared radiation (SWIR), while the robust synthesis of the environmentally friendly bright emitter is elusive.

Therefore, a substantial research effort on the synthesis of Indium Arsenide colloidal QD has taken place as a promising candidate for NIR light-emitting applications. Despite the synthetic protocols for the synthesis of  InAs QDs that have been reported in the last decade, only very recently a novel synthetic scheme has been introduced, producing air-stable, bright InAs/ZnSe QDs emitting in NIR.5 Here, we study the photo-physics of the InAs/ZnSe QDs with steady-state and time-resolved absorption and photoluminescence spectroscopy, while we probe the gain dynamics of the system showing an ultrafast gain lifetime and low amplified stimulated emission thresholds in NIR.

15:15 - 15:30
3C2-O2
Krahne, Roman
Italian Institute of Technology (IIT)
Epsilon-Near-Zero Cavities for Light-Matter Interaction and Emission Tuning
Krahne, Roman
Italian Institute of Technology (IIT), IT
Authors
Roman Krahne a, Vincenzo Caligiuri b, Bruno Zappone b, Antonio De Luca b, Aniket Patra a
Affiliations
a, Italian Institute of Technology (IIT), Via Morego 30, Genova, IT
b, Department of Physics, University of Calabria, via P. Bucci, 31C, 87036, Rende (CS), Italy
Abstract

Layered metal-dielectric-metal (MDM) cavities sustain resonances with vanishing dielectric permittivity that can couple to the light emission of fluorophores positioned either on their surface [1] or within the cavity [2]. The wavelength of the cavity resonance depends on the polarization, the angle, and the thickness of the dielectric layer.[3] In the weak coupling regime, the polarization and angular properties of the MDM cavity resonances are transferred to the emission of the fluorophores inside the dielectric layer of the cavity. [2] In the strong coupling regime, the interaction of the cavity modes with the excitonic emission of the fluorophores leads to the formation of polaritons and Rabi splitting of the resonance modes.[4] Typically, the dispersion of the Rabi splitting is mapped by varying the k-vector that is in-plane with the emitter and mirror layers, for example by imaging the angle-dependent signal in the back focal plane of the objective. [4] Another option to tune the cavity resonance is to vary the length of the photonic cavity (thereby varying the out-of-plane k-vector), however, this is difficult to achieve, for example via the tedious fabrication of several samples with different dimensions.

Here we present an elegant method to vary the thickness of the dielectric layer (that corresponds to the length of the cavity) in situ by using a surface-forces apparatus (SFA). [5] In this experiment, two cylindrical and semitransparent mirrors are separated by a dielectric liquid in which the light emitting nanocrystals or molecules are dispersed. The distance of the mirrors can be controlled by a cantilever spring over the range from large (mm) separation to almost close contact. Here a crossed configuration of the cylindrical mirrors results in a well-defined contact region with sub-millimeter dimension. Such a SFA therefore acts as a tunable MDM cavity that allows to detect the strong coupling of multiple cavity harmonics with the dye emission in a single, rapid, and continuous sweep of cavity thickness. We observed Rabi splitting exceeding 100 meV, and we analyze the Rabi splitting of the different cavity harmonics, finding a square root dependence with respect to the number of the involved emitters.

Furthermore, we prepared planar MDM cavities with fixed dimension and investigated the Rabi splitting via the angle-dependence with spectroscopic ellipsometry. These experiments demonstrated that the polaritons inherit the ENZ character of the cavity modes. The complementarity of this experiment with the SFA study allows to investigate the impact of the in-plane and out-of-plane k vector on the Rabi splitting.

References

[1] V. Caligiuri, M. Palei, M. Imran, L. Manna, R. Krahne, ACS Photonics 2018, 5, 2287-2294.

[2] V. Caligiuri, G. Biffi, M. Palei, B. Martín-García, R. D. Pothuraju, Y. Bretonnière, R. Krahne, Adv. Opt. Mater. 2020, 8, 1901215.

[3] V. Caligiuri, M. Palei, G. Biffi, S. Artyukhin, R. Krahne, Nano Lett. 2019, 19, 3151-3160.

[4] A. Patra, V. Caligiuri, R. Krahne, A. De Luca, Adv. Opt. Mater. 2021, 9, 2101076

[5] A. Fieramosca, et al., Sci Adv. 2019;5(5):eaav9967.

[6] B. Zappone, V. Caligiuri, A. Patra, R. Krahne, A. De Luca, ACS Photonics 2021.

15:30 - 15:45
3C2-O3
Leemans, Jari
Gent University - BE
Colloidal III-V Quantum Dot Photodiodes for Short-Wave Infrared Photodetection
Leemans, Jari
Gent University - BE, BE
Authors
Jari Leemans a, Vladimir Pejovic b, Epimitheas Georgitzikis b, Matthias Minjauw a, Abu Bakar Siddik b, Yuhao Deng a, Yinghuan Kuang b, Gunther Roelkens a, Christophe Detavernier a, Itai Lieberman b, Pawel Malinowski b, David Cheyns b, Zeger Hens a
Affiliations
a, Ghent University (BE)
b, imec vzw., Kapeldreef 75, Leuven, 3001, BE
Abstract

Short-wave infrared (SWIR) image sensors based on colloidal quantum dots (QDs) are characterized by low cost, small pixel pitch, and spectral tunability. Adoption of QD-SWIR imagers is, however, hampered by a reliance on restricted elements such as Pb and Hg. Here, QD photodiodes, the central element of a QD image sensor, made from non-restricted In(As,P) QDs that operate at wavelengths up to 1400 nm are demonstrated. Three different In(As,P) QD batches that are made using a scalable, one-size-one-batch reaction and feature a band-edge absorption at 1140, 1270, and 1400 nm are implemented. These QDs are post-processed to obtain In(As,P) nanocolloids stabilized by short-chain ligands, from which semiconducting films of n-In(As,P) are formed through spincoating. For all three sizes, sandwiching such films between p-NiO as the hole transport layer and Nb:TiO2 as the electron transport layer yields In(As,P) QD photodiodes that exhibit best internal quantum efficiencies at the QD band gap of 46±5% and are sensitive for SWIR light up to 1400 nm.

15:45 - 16:00
3C2-O4
Di stasio, Francesco
Istituto Italiano di Tecnologia (IIT)
Near-Infrared Light-emitting diodes based on RoHS complaint colloidal semiconductor quantum dots
Di stasio, Francesco
Istituto Italiano di Tecnologia (IIT), IT

Dr. Francesco Di Stasio obtained a Ph.D. in Physics at University College London (UK) in 2012. He then worked as a research Scientist at Cambridge Display Technology (Sumitomo Chemical group, UK) until he undertook postdoctoral research at the Istituto Italiano di Tecnologia (IIT, Italy). In 2015 he was awarded a Marie Skłodowska-Curie Individual Fellowship at the Institute of Photonic Sciences (ICFO, Spain). Since 2020 he is Principal Investigator of the Photonic Nanomaterials group at IIT after being awarded an ERC Starting grant. Francesco is a materials scientist with more than 10 years of research experience in optoelectronics.

Current research interests and methodology: Nanomaterials for classical and non-classical light-sources: This research activity focuses on the investigation of synthetic routes to obtain highly luminescent semiconductor colloidal nanocrystals and exploit such material in light-emitting diodes (LEDs). Here, we study how chemical treatments of colloidal nanocrystals can promote enhanced performance in devices, and physico-chemical properties of nanocrystals (e.g. self-assembly and surface chemistry) can be exploited to fabricate optoelectronic devices with innovative architectures. Novel methods and materials for light-emitting diodes: The group applies materials science to optoelectronics by determining which fabrication parameter lead to enhanced performance in LEDs. In order to transition from classical to non-classical light-sources based on colloidal nanocrystals, the group is developing novel methods for controlling the deposition and positioning of an individual nanocrystals in the device. Both “top-down” and “bottom-up” approaches are investigated.

Authors
Manuela De Franco a, c, Houman Bahmani Jalali a, d, Dongxu Zhu d, Luca De Trizio d, Mirko Prato b, Liberato Manna d, Francesco Di stasio a
Affiliations
a, Photonic Nanomaterials group, Istituto Italiano di Tecnologia, Via Morego 30, 16163 Genova, Italy
b, Materials Characterization Facility, Istituto Italiano di Tecnologia, Genoa, Italy
c, Dipartimento di Chimica e Chimica Industriale, Università degli Studi di Genova, Via Dodecaneso, 31, 16146, Genova, Italy​
d, Nanochemistry, Istituto Italiano di Tecnologia (IIT), via Morego 30, 16163 Genova, Italy.​
Abstract

Near-infrared Light-emitting diodes (NIR-LEDs) based on colloidal semiconductor quantum dots (QDs) are of interest for a variety of optoelectronic applications such as hyperspectral and biomedical imaging, night vision and telecommunication systems. Importantly, all efficient NIR-LEDs based on QDs employ toxic heavy metals compositions [1] while The European Union’s “Restriction of Hazardous Substances” (RoHS) directive limits the use of such compounds. Colloidal indium arsenide QDs are emerging as a promising candidate for NIR applications[2] thanks to their low toxicity and recent progresses in material synthesis leading to stable and highly efficient QDs [3]. Here, we fabricated NIR-LEDs emitting in the range of 800-1000 nm based on heavy metal-free efficient InAs/ZnSe core-shell QDs (PLQY >40%) [3]. The resulting external quantum efficiency of NIR-LEDs benefited from nanoengineering at both material and device levels. This study demonstrates that InAs based QDs are a promising nanomaterial for the fabrication of optoelectronic devices operating in the NIR.

16:00 - 16:15
3C2-O5
Hermerschmidt, Felix
Humboldt-Universität zu Berlin
Printed Hybrid and ITO-Free Optoelectronic Devices
Hermerschmidt, Felix
Humboldt-Universität zu Berlin, DE
Authors
Felix Hermerschmidt a, Vincent R.F. Schröder b, Theodoros Dimopoulos c, Eva L. Unger d, e, Emil J.W. List-Kratochvil a, b
Affiliations
a, Humboldt‐Universität zu Berlin, Institut für Physik, Institut für Chemie, IRIS Adlershof, Zum Großen Windkanal 2, 12489 Berlin, Germany
b, Helmholtz-Zentrum Berlin für Materialien und Energie,, Hahn-Meitner-Platz, 1, Berlin, DE
c, AIT Austrian Institute of Technology, Center for Energy, Energy Conversion and Hydrogen, Giefinggasse, 2, Wien, AT
d, Young Investigator Group Hybrid Materials Formation and Scaling, Helmholtz-Zentrum Berlin für Materialen und Energie GmbH, Kekuléstraße 5, 12489 Berlin, Germany.
e, Chemical Physics and Nano Lund, Lund University, P.O. Box 124, Lund 22100, Sweden
Abstract

The use of solution‐based materials is the key to making new devices accessible within the field of organic and hybrid electronics. It also enables manufacturing at a high-throughput industrial scale, by being compatible with scalable fabrication techniques, such as inkjet printing. This technique offers both the capabilities of coating as well as precise control of the deposited material during processing. Expanding these capabilities to combinatorial inkjet printing allows the deposition of multiple inks in a single printing step – again, with precise control of the droplet ratio during printing – to produce films with tunable composition.

One class of solution-processed materials utilisable in this way are metal halide perovskites, which have contributed to significant performance increases when employed as active material in solar cells and hybrid light-emitting diodes (LEDs) during the past decade. However, no active material can function alone in an optoelectronic device, but must be sandwiched between two electrodes, of which at least one must be transparent. By moving away from the ubiquitous material indium tin oxide (ITO), a wide variety of transparent conducting electrodes can be utilised that overcome some of the inherent limitations of ITO, such as its brittleness.

This contribution highlights our work on these two main avenues of optoelectronic device research: the processing of active materials in hybrid and organic optoelectronics [1-3], and the implementation of ITO-free transparent conducting electrodes [4-7]. The findings presented address the importance of continuing work in organic and hybrid (opto)electronic devices, in order to move towards high performance flexible electronics.

16:15 - 16:30
3C2-O6
Sánchez, Rafael
Universitat Jaume I, Institute of Advanced Materials (INAM) - Spain
Understanding the photo-electrochemical mechanisms that determine the performance of light-emitting devices based on low-cost semiconductors
Sánchez, Rafael
Universitat Jaume I, Institute of Advanced Materials (INAM) - Spain, ES

Rafael Sánchez (M.Sc. degree in Chemistry in 2006 and Ph.D. degree in 2011, both from the Universitat Autònoma de Barcelona, Spain). To date, he has worked without interruptions in several international research institutions: Universitat Jaume I (2012-2017), University of Liverpool (2017-2018), Henkel Ibérica-UAB (2018-2019) and Université de Bordeaux (2019-2020). The main research topics he has developed are based on the synthesis and electro-optical characterization of functional materials and/or semiconductors for light generation, photovoltaics and water splitting applications. His current interests are focused on the chemical design and synthesis of quaternary diazaaromatic dications for the development of novel 2D metal halide perovskite semiconductors suitable for the preparation low-cost, highly efficient and durable optoelectronic devices. He is the author of 1 book chapter and 27 publications in peer-review international journals (27 publications in Q1 journals, 18 of which in D1 journals with impact factor > 6.9 in different areas) with 2733 citations and a h-index of 21 (https://scholar.google.es/citations?user=kzbjcFQAAAAJ&hl=es).

Authors
Rafael Sánchez a
Affiliations
a, The Research Institute of Advanced Materials at the University Jaume I, Avinguda de Vicent Sos Baynat, s/n, Castelló de la Plana, ES
Abstract

Nowadays, one of the most urgent societal challenges is focused on the progressive reduction of the global energetic consumption and pollution. Considering that lighting accounts for the 15 percent of the global electricity consumption and 5 percent of the worldwide greenhouse gas emission, new technological strategies are required in order to tackle and revert the current energetic troublesome. To reach that goals, not only the development of new materials and light-emitting technologies are required, but also a complete understanding of their working principles and mechanisms involved in the charge-to-photon conversion is a mandatory field. In this talk, I will discuss about the performance of a series of light-emitting diodes (LEDs) based on different semiconductors, e.g. lead-based and lead-free halide perovskites, II-VI and IV-VI quantum dots (QDs), fabricated through different approaches aimed at improving their performance and/or inducing synergies between the light-active materials. In addition, I will show the experimental tools and techniques employed to elucidate the photo-electrochemical mechanisms behind their functioning, which in turn determine their efficiency, brightness, durability and other relevant parameters.

16:30 - 16:45
Closing
 
Posters
Dominic Guggisberg, Sergii Yakunin, Christoph Neff, Marcel Aebli, Detlef Günther, Maksym Kovalenko
Non-Hydrolytic Sol-Gel Reactions for Thin CsPbX3 Nanocrystal Coatings
sarika kumari
Self-assembled molecule PDINO as electron-transporting layer for CdSe@ZnS Quantum Dot Light Emitting Diodes
Taras Sekh, Ihor Cherniukh, Gabriele Rainò, Chenglian Zhu, Yevhen Shynkarenko, Rohit Abraham John, Olivia Ashton, Etsuki Kobiyama, Rainer Mahrt, Thilo Stöferle, Rolf Erni, Maryna Bodnarchuk, Maksym Kovalenko
Co-assembly of Lead Halide Perovskite Nanocrystals and Dielectric Nanodiscs into Multicomponent Functional Superlattices
Mariia Svyrydenko, Viktoriia Morad, Andriy Stelmakh, Leon Feld, Marcel Aebli, Andrij Baumketner, Maksym V. Kovalenko
Tail Engineering of Zwitterionic Phospholipid Ligands for Improving Colloidal Stability of Lead Halide Perovskite Nanocrystals
Gopa Sardar, Atul Shukla, Evan G. Moore, Gangadhar Banappanavar, Shin-Chun Lo, Ebinazar Namdas, Dinesh Kabra
Reduced Singlet-Triplet Annihilation for Low Threshold Amplified Spontaneous Emission from Blue Polyfluorene Electroluminescent Organic Semiconductor
Ales Vlk, Nada Mrkyvkova, Vladimir Held, Peter Nadazdy, Eva Majkova, Matej Jergel, Martin Ledinsky, Antonin Fejfar, Peter Siffalovic
Combined in-situ PL and GIWAXS study of halide perovskite formation
Giannis Antoniou, Panagiotis Keivanidis
Up-converted Luminescence of 9,10 diphenyl-Anthracene Solutions Sensitized by a Doubly-photoexcited Metallorganic Complex: Conciliating Spectroscopic Measurements with Photokinetic Modelling
Daria Markina, Anatoly Pushkarev, Sergey Makarov
Lead halide perovskite nanolasers as a new platform for sensitive hydrogen halide vapor detection
Rodolfo Canet-Albiach, Marie Krecmarova, José José Bosch Bailach, Andrés F. Gualdrón-Reyes, Jesús Rodríguez-Romero, Setatira Gorji, Hamid Pashaei-Adl, Iván Mora-Seró, Juan P. Martínez Pastor, Juan Francisco Sánchez-Royo, Guillermo Muñoz Matutano
Revealing Giant Exciton Fine-Structure Splitting in 2D Perovskites using van der Waals Passivation
Michael Hengge, Paul Hänsch, Daniel Ehjeij, Frank S. Benneckendorf, Jan Freudenberg, Uwe H.F. Bunz, Klaus Müllen, Emil J.W. List-Kratochvil, Felix Hermerschmidt
Novel Bisazide for Universal Crosslinking of Polymer Light Emitting Materials
Setatira Gorji, Hamid Pashaei Adl, Ivan Alarcon, Isaac Suárez, Pablo F. Betancur, Vladimir Chyrvony, María Cristina Momblona, Teresa Ripolles Sanchis, Rafael Abargues, Pablo P. Boix, Juan Martínez Pastor, Guillermo Muñoz Matutano
Strong coupling between TEA2SnI4 perovskite emission and open access fiber cavities at room temperature
Guillermo Muñoz Matutano, Marie Krecmarova, Setatira Gorji, Alejandro Molina, María C. Asensio, Andrés F. Gualdrón-Reyes, Jesús Rodríguez-Romero, Hamid Pashaei-Adl, Rodolfo Canet-Albiach, Luca Schio, Massimo Tormen, Luca Floreano, Iván Mora-Seró, Juan Martínez Pastor, Juan Francisco Sánchez-Royo
Donor-acceptor discrete optical emission in 2D perovskites
Shovon Chatterjee, Arghya Sen, Pratik Sen
Green Synthesis of Pure Inorganic 3D and Ruddlesden-Popper Quasi 2D Cesium Lead Halide Perovskite Nanocrystals in Menthol-Based Deep Eutectic Solvents
Nathan Rafisman, Yehonadav Bekenstein, Lev Chuntonov, Arghyadeep Basu
Investigating the Role of Thiocyanate on the Surface of CsPbBr3 Nanocubes.
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