The program is in CEST Time.

Program
 
Thu Sep 15 2022
08:00 - 09:50
Registration
09:50 - 10:00
nanoGe Introduction and opening
Session 1A
Chair not set
10:00 - 10:30
1A-I1
De Feyter, Steven
KU Leuven
On-surface synthesis of monolayer metal organic frameworks and covalent organic frameworks, as revealed by in situ scanning tunneling microscopy
De Feyter, Steven
KU Leuven, BE

Steven De Feyter is a professor of chemistry at KU Leuven in Belgium. After completing his PhD with Prof. F. C. De Schryver at KU Leuven in 1997, he moved for a postdoctoral position to the group of Prof. Ahmed Zewail (California Institute of Technology, Pasadena). He was awarded an ERC advanced grant in 2013, and was associate editor of the RSC journal Chemical Communications for 10 years. He is elected member of the Royal Flemish Academy of Belgium for Science and the Arts. Nano(bio)chemistry on surfaces is the core activity of his research group. To please the “seeing is believing” desire, the team uses high-resolution scanning probe microscopy techniques, sometimes combined with optical microscopy techniques, to unravel the beauty and function of multi-(bio)molecular assemblies on surfaces.

Authors
Steven De Feyter a
Affiliations
a, Department of Chemistry, KU Leuven, BE, Celestijnenlaan, 200F, Leuven, BE
Abstract

Unraveling the structure and dynamics of formation of covalent and non-covalent organic based 2D crystalline materials is key to control the quality of these materials, i.e. the defect density, and their size. These characteristics are important to understand and control their properties. In this contribution, our efforts on the use of scanning probe microscopy, and in particular scanning tunneling microscopy (STM), to visualize the structure and the dynamics of formation of substrate-supported metal organic frameworks (sMOF) and substrate-supported covalent organic frameworks (sCOF), at the liquid-solid interface, are highlighted.

It is shown that the quality of monolayer metal organic frameworks (MOF) depends critically on the solvent mixture. Moreover, using chiral solvents, homochiral lattices can be formed, in case of the metal containing supramolecular networks, while no chiral induction is observed in absence of the metal ion.

Covalent organic frameworks are formed based on boroxine chemistry. We report on a model boroxine 2D dynamic covalent polymer, and unveil both qualitative and quantitative details of the nucleation–elongation processes in real time and under ambient conditions. Sequential data analysis enable observation of the amorphous-to-crystalline transition, the time-dependent evolution of nuclei, the existence of ‘non-classical’ crystallization pathways and, importantly, the experimental determination of essential crystallization parameters with excellent accuracy, including critical nucleus size, nucleation rate and growth rate. In addition, we show that in specific cases, the electric field between the STM tip and the substrate can induce, on demand, the polymerization or depolymerization process.

10:30 - 11:00
1A-I2
Lackinger, Markus
Technische Universität München, Germany
On-Surface Photopolymerization – A Pathway for the Synthesis of Mesoscale-Ordered 2D Polymers
Lackinger, Markus
Technische Universität München, Germany, DE

Markus Lackinger currently leads a research group at the Deutsches Museum – one of Germany’s largest research museums and member of the Leibniz Association, in close collaboration with the Technische Universität München.

He studied physical engineering at the University of Applied Sciences in Munich and received his Ph.D. in experimental physics from Chemnitz University of Technology in 2003. During his graduate studies, he had a research stay at Columbia University with Prof. George W. Flynn, and afterwards he did a Postdoc with Prof. Wilson Ho at the University of California, Irvine. In 2006 he became a junior research group leader and later on substitute professor at the Ludwig-Maximilians-University Munich.

He has been scientifically socialized in surface science and always had a keen interest in molecular structures. In this context, the development of protocols and novel approches for the synthesis of ever more extended 2D polymers on solid surfaces and the thorough characterization of their structures and properties now consitutes one of his major reasearch interests and goals.

Authors
Lukas Grossmann a, Benjamin T. King b, Jonas Björk c, Markus Lackinger a
Affiliations
a, Deutsches Museum, Museumsinsel 1, 80538 München and Physics Department, Technische Universität München, James-Franck-Strasse 1, 85748 Garching (Germany)
b, Department of Chemistry, University of Nevada, North Virginia Street, 1664, Reno, US
c, Department of Physics Chemistry and Biology Linköping University, 83, 581, SE
Abstract

We attained the synthesis of mesoscale ordered 2D polymers by the topochemical on-surface photopolymerization of fluorinated anthracene-triptycene (fantrip) monomers. The underlying protocol is two-staged: (1) Self-assembly of the monomers into a photopolymerizable monolayer structure, where the photoactive anthracene moieties are face-to-face stacked; (2) cross-linking of the self-assembled monolayer into a covalent 2D polymer by photochemically excited [4+4] cycloadditions between the antiparallel aligned anthracene blades. Thereby, the long-range order attained in (1) is transferred into the covalent state. Yet, the topochemical approach crucially depends on achieving the reactive packing with the appropriate mutual alignment of the anthracene blades. For the self-assembly the underlying surface plays a decisive role. We used graphite substrates, but additional passivation with an alkane monolayer was necessary to weaken molecule-surface interactions. As a result, the desired monolayer that is determined by molecule-molecule interactions became thermodynamically favored. STM has proven as ideal analytical tool for monitoring intermediate and final structures with the ultimate single-linkage resolution. The [4+4] cycloadditions induce a sizable increase of the HOMO-LUMO gap, which translates into an unambiguous change of STM contrast. This possibility to identify individual newly formed covalent linkages facilitated studies of the polymerization progression and allowed to assess the temperature dependence of polymerization rates, where an increase with temperature indicated a small energy barrier in the photoexcited state. In addition, successful photopolymerization could be corroborated by complementary local IR spectroscopy.

11:00 - 11:30
Coffee Break
11:30 - 12:00
1A-I3
Félix, Zamora
Universidad Autonoma de Madrid, ES
Processability of Imine-based 2D Covalent Organic Frameworks: The Role of the Nanostructure Aggregation
Félix, Zamora
Universidad Autonoma de Madrid, ES, ES

Dr. Felix Zamora is Full Professor at the Department of Inorganic Chemistry UAM, research associate member of IMDEA Nanoscience Foundation (Excelencia Severo Ochoa), Institute for Advanced Research in Chemical Sciences (IAdChem), and Condensed Matter Physics Institute Center (IFIMAC; Excelencia Maria de Maeztu). He has been recently awarded by the Spanish Royal Society of Chemistry with Research Excellence Award in 2015. Félix Zamora has obtained the position of distinguished professor with the mention of the Excellence Program for University Professors of the CAM (2020).
F. Zamora is head of the Nanomaterials Laboratory (nanomater.es). His research activity can be summarized in 225 papers in scientific journals (H= 44, 9707 citations from Scopus) in the area of nanoscience, material science, multidisciplinary chemistry, and inorganic chemistry, (Nature Nanotech, Nature Commun., Chem Soc Rev, Angewandte Chem., JACS, Chem. Sci., Adv. Mater., ACS Nano,..) and 10 patents (2 transferred to a company). In addition to three chapters in books and several scientific reviews (Chem Soc Rev, Coord Chem Rev, Adv Mater, ...). More than 75 national and international invited talks at Universities and Conferences.
His recent research has focused on: i) the preparation and characterization of new nanomaterials with multifunctional properties, including molecular wires based on 1D-coordination polymers and lamellar coordination polymers to produce 2D-polymers and films; ii) Porous materials based on Covalent Organic Frameworks; iii) Alternative 2D materials to graphene (“antimonene” isolation in 2016). He has spent several periods as a visiting professor at the Nanoscience Laboratory (University of Newcastle; 2 summer periods: 2010/2012), at the Chemistry Department of the National University of Singapore, and at the Singapore Graphene Center (6 summer periods: 2013, 2015-2019).
Since 2013, he is a member of the editorial board member of Scientific Reports (Nature Publishing Group) and from 2017 of General Chemistry Journal and Editor-in-Chief of "Inorganic Materials and Metal-Organic Frameworks" section of Nanomaterials Journal MDPI.
He has developed I+D projects with several companies Abengoa Research, Nanoinnova Tech., Repsol, and Fourteen Energies. He is the founder and scientific advisor of the companies Nanoinnova Technologies S.L. (founded in 2008, UAM spin-off company, www.nanoinnova.com), Porous Inks Technologies S.L. (founded in 2020, UAM spin-off company), and Fourteen Energies S.L. (founded in 2019, UAM spin-off company).

Authors
Zamora Félix a, Rodriguez-San Miguel David a, Martín Jesus A. a, Royuela Sergio a, Puigmartí-Luis Josep b, Maspoch Daniel c
Affiliations
a, Departamento de Química Inorgánica, Universidad Autónoma de Madrid, 28049 Madrid, España, Madrid, ES
b, Departament de Ciència dels Materials i Química Física, Institut de Química Teòrica I Computacional, Carrer de Jordi Girona, 20, Barcelona, ES
c, Catalan Institute of Nanoscience and Nanotechnology, Carrer del Rosselló, 161, Barcelona, ES
Abstract

Covalent Organic Frameworks (COFs) are porous and ordered organic materials formed by condensation reactions of organic molecules. Recently, the Schiff-base chemistry or dynamic imine-chemistry has been explored for the synthesis of new COFs. The main reason for this tendency is the higher chemical stability, porosity, and crystallinity that they show in comparison to those previously reported, e.g. boronate ester-based COFs. The most typical imine-based COF structures are bidimensional and their synthesis can produce nanolayers or flakes of different lateral dimensions. This talk will summarize the most recent progress in preparing imine-based COFs that enable their processability. We will observe that the control of the COF-nanoparticle aggregation plays a fundamental role in the material processability. I will show some recent examples of 3D-printing of imine-based COFs and imine-based COF gels' formation and their transformation into aerogels and films to form functional centimeter-long membranes. Finally, I will provide some perspectives on the potential applications of these materials.

 

12:00 - 12:30
1A-I4
Backes, Claudia
University of Kassel
Production of organic nanomaterials by liquid phase exfoliation
Backes, Claudia
University of Kassel, DE
Authors
Claudia Backes a
Affiliations
a, Physical Chemistry of Nanomaterials, University of Kassel, Heinrich-Plett-Straße, Kassel, DE
Abstract

Liquid phase exfoliation (LPE) has become an important production technique giving access to single and few-layered nanosheets in colloidal dispersion. It is applicable to a whole host of inorganic crystals with the nanosheet morphology being defined by the in plane and out of plane binding strength in the parent crystal.[1] While LPE can be applied to layered crystalline organic sheet stacks, the mechanism of the exfoliation is less understood than in the case of inorganic materials. In particular, it is not clear which factors govern the exfoliability. This is mostly because post-exfoliation processing can have an impact in the nanosheet dimensionality making comparisons challenging.

Here, we apply our learning from the exfoliation of layered inorganic materials to 2D crystals. In particular, we suggest that the exfoliability can be assessed by statistical AFM analysis to determine the length/thickness aspect ratio or characteristic monolayer length. First, we applied this methodology to 2D polymers synthesized by the single crystal to single crystal transformation. We found that crystalline nanosheets are produced after LPE of charge-neutral polymers with yield and sheet morphology similar to graphite exfoliation giving nanosheets with average length/thickness aspect ratios of ~60.[2] In contrast, LPE of metal organic frameworks (MOFs) yields relatively small and thick sheets. Using a Zr-MOF as model system, an average length/thickness aspect ratio of ~6 was determined which is significantly lower than for most layered inorganic materials.[3] In a comparative study using a range of Ga, Sc and Zr-based MOFs we find that the aspect ratio varies between 4-10 when performing LPE in aqueous surfactant. The length/thickness aspect ratio cannot be rationalized on the basis of intersheet binding strength and we suggest that porosity has a positive impact on the exfoliability.

Finally, we were intrigued by the question whether molecular crystals with only noncovalent bonds between discrete molecules could be exfoliated using LPE. With the realisation that the binding strength anisotropy governs the (average) shape of the LPE nanomaterials, it should be possible to obtain nanomaterials with distinct shape from exfoliation of organic molecular crystals. To test this, orthorhombic and triclinic single crystals of the organic semiconductor rubrene were used in LPE.[4] Distinct nanorods and nanobelts of rubrene with only a few molecular layers are formed, stabilised against aggregation in aqueous sodium cholate solution and isolated by liquid cascade centrifugation.

12:30 - 14:30
Lunch
Session 1B
Chair not set
14:30 - 15:00
1B-I1
Donglin, Jiang
Department of Chemistry, National University of Singapore
Abstract to be confirmed
Donglin, Jiang
Department of Chemistry, National University of Singapore, SG
Authors
Jiang Donglin a
Affiliations
a, Department of Chemistry, National University of Singapore, SG, Lower Kent Ridge Road, 21, Singapore, SG
Abstract

Organic 2D Crystalline Materials: Chemistry, Physics and DevicesOrganic 2D Crystalline Materials: Chemistry, Physics and DevicesOrganic 2D Crystalline Materials: Chemistry, Physics and DevicesOrganic 2D Crystalline Materials: Chemistry, Physics and DevicesOrganic 2D Crystalline Materials: Chemistry, Physics and DevicesOrganic 2D Crystalline Materials: Chemistry, Physics and DevicesOrganic 2D Crystalline Materials: Chemistry, Physics and DevicesOrganic 2D Crystalline Materials: Chemistry, Physics and DevicesOrganic 2D Crystalline Materials: Chemistry, Physics and DevicesOrganic 2D Crystalline Materials: Chemistry, Physics and DevicesOrganic 2D Crystalline Materials: Chemistry, Physics and DevicesOrganic 2D Crystalline Materials: Chemistry, Physics and DevicesOrganic 2D Crystalline Materials: Chemistry, Physics and DevicesOrganic 2D Crystalline Materials: Chemistry, Physics and DevicesOrganic 2D Crystalline Materials: Chemistry, Physics and DevicesOrganic 2D Crystalline Materials: Chemistry, Physics and DevicesOrganic 2D Crystalline Materials: Chemistry, Physics and DevicesOrganic 2D Crystalline Materials: Chemistry, Physics and DevicesOrganic 2D Crystalline Materials: Chemistry, Physics and DevicesOrganic 2D Crystalline Materials: Chemistry, Physics and DevicesOrganic 2D Crystalline Materials: Chemistry, Physics and DevicesOrganic 2D Crystalline

15:00 - 15:30
1B-I2
Mateo-Alonso, Aurelio
POLYMAT, University of the Basque Country UPV/EHU, ES
Merging Distorted Nanographenes and Framework Materials
Mateo-Alonso, Aurelio
POLYMAT, University of the Basque Country UPV/EHU, ES, ES
Authors
Aurelio Mateo-Alonso a, b
Affiliations
a, POLYMAT, University of the Basque Country UPV/EHU, Tolosa Hiribidea, 72, Donostia, ES
b, IKERBASQUE, Basque Foundation for Science, Plaza Euskadi 5, 48009 Bilbao, Spain
Abstract

Nanographenes –polycyclic aromatic hydrocarbons that extend over 1 nm– can adopt a broad range of non-planar conformations that challenge the perception of aromatic systems as rigid and flat structures. Such distorted structures are the result of the steric strain induced by overcrowding or congestion in key positions of the aromatic core. Distorted nanographenes have shown enhanced solubility and unique optoelectronic and chiroptical properties as an effect of their distorted molecular structure. Our group has pioneered the introduction of distorted nanographenes in framework materials [1-5]. This merge offers new possibilities in the design monomers with symmetries that deviate from standard graphitic geometries, and in turn, in the design of organic frameworks with unprecedented architectures and properties. The most recent advances of these distorted framework materials including synthetic routes, optoelectronic properties, self-organising properties, and potential applications will be discussed.                                   

 

 

 

 

 

15:30 - 15:45
1B-T1
Wang, Zhiyong
On-Water Surface Synthesis of Charged Two-Dimensional Polymer Crystals Enabling Effective Ion Transport
Wang, Zhiyong
Authors
Zhiyong Wang a, b, Renhao Dong b, Xinliang Feng a, b
Affiliations
a, Max Planck Institute of Microstructure Physics, 06120 Halle, Germany, Weinberg, 2, Halle (Saale), DE
b, Center for Advancing Electronics Dresden (cfaed) & Faculty of Chemistry and Food Chemistry, , Germany, Technische Universität Dresden, 01069 Dresden, Alemania, Dresden, DE
Abstract

Synthetic two-dimensional polymers (2DPs) are an emerging class of structurally-defined crystalline materials that comprise covalent networks with topologically planar repeat units. Yet, synthesizing 2DP single crystals via irreversible reactions remains challenging. Herein, utilizing the surfactant-monolayer-assisted interfacial synthesis (SMAIS) method, few-layer, large-area, skeleton-charged 2DP (C2DP) single crystals were successfully synthesized through irreversible Katritzky reaction, under pH control. The resultant periodically ordered 2DPs comprise aromatic pyridinium cations and counter BF4- anions. The representative C2DP-Por crystals display a tunable thickness of 2-30 nm and a lateral size up to 120 μm2. Using imaging and diffraction methods, a highly uniform square-patterned structure with the in-plane lattice of a = b = 30.5 Å was resolved with near-atomic precision. Significantly, the C2DP-Por crystals with cationic polymer skeleton and columnar-like pore arrays offer a high chloride ion selectivity with a coefficient up to 0.9, thus ensuring the integration as the anion-selective membrane for the osmotic energy generation. Our studies reveal a route to synthesize 2DP single crystals using a kinetically controlled irreversible reaction and will propel the development of membrane-based energy-conversion technologies.

15:45 - 16:00
1B-T2
Lieberwirth, Ingo
Max Planck Institute for Polymer Research, Mainz
Nanoscale control of the surface functionality of polymeric 2D materials
Lieberwirth, Ingo
Max Planck Institute for Polymer Research, Mainz, DE
Authors
Ingo Lieberwirth a
Affiliations
a, MPI for Polymer Research, Ackermannweg 10, Mainz, 55128, DE
Abstract

We report on a novel concept for the production of two-dimensional organic nanoplateletts, which allows us to design the local surface chemistry. These nanoplateletts are polymer single crystals with a lamellar morphology.  Usually, these two-dimensional crystalline nanoplateletts have a homogeneous surface and structuring them is a major challenge. In this study we show the preparation of lamellar polymer crystals having a defined molecular thickness and in addition showing a core-rim architecture. The central area has a different chemical group on the surface than the peripheral area. We achieve this by sequential crystallization driven self assembly of precisely synthesized polymers with different functional groups in the main chain. We demonstrate the resulting structure of the nanoplateletts by means of fluorescent labeling and a selective chemical precipitation reaction at the hydroxyl groups located exclusively at the rim of the plateletts. The resulting polymeric two-dimensional platelets are obtained in a stable dispersion, which simplifies further processing and makes both crystal surfaces accessible for subsequent functionalization. A variety of polymers can be used, which keeps the process and the choice of surface functionalization very flexible. This new concept of designing surface chemistry thus opens up new possibilities in the field of nanotechnology.

16:00 - 16:15
1B-T3
Segura, Jose L.
Universidad Complutense de Madrid
Two-dimensional Covalent Organic Frameworks for Energy Related Applications
Segura, Jose L.
Universidad Complutense de Madrid, ES

Jose´ L. Segura obtained his PhD in Organic Chemistry at the UCM in Madrid working in Organic materials. After a stay in W. Dailey’s group (Univ. Pennsylvania) he performed postdoctoral stays in the groups of M. Hanack (Univ.Tüingen), F. Wudl (UCSB, USA),and P. Bäuerle (Univ. Ulm). In 1995 Prof. Segura joined the faculty at the Complutense University in Madrid where he is currently Full Professor and is leading the Group of Macromolecular
and Heterocyclic Organic Materials. Current research interests involve synthesis, electrochemical and photophysical
characterization of molecular and macromolecular electroactive systems for optoelectronics as well as in the de novo synthesis and post-synthetic functionalization of Covalent Organic Frameworks for energy-related applications. 

Authors
Jose L. Segura a, Marcos Martínez-Fernández a, Alejandro de la Peña a, b, Elena Gala a, b, Marta Gordo Lozano a, Matías J. Alonso-Navarro a, b, Fátima Suárez Blas a, b, M. Mar Ramos b
Affiliations
a, Departamento Química Orgánica I, Facultad Ciencias Químicas, Universidad Complutense de Madrid, E-28040, Madrid, Spain.
b, Departamento de Tecnología Química y Ambiental, Univ. Rey Juan Carlos, Móstoles, 28933, Spain
Abstract

Covalent organic frameworks (COFs) comprise an emerging class of materials based on the atomically precise organization of organic subunits into two- (2D) or three-dimensional (3D) porous crystalline structures connected by strong covalent bonds with predictable control over composition and topology.[1]

In our research group we are dealing with the synthesis of COFs based on imine[2] and/or imide linkages[3] by using both de novo synthesis and post-synthetic approaches.[4-9] We have addressed the issue of the  processability of COFs to get  suitable material dispersions. For this purpose,  liquid phase exfoliation (LPE) assisted by sonication and chemical exfoliation (CE) have shown to be easy and scalable methods to disrupt the non-covalent interactions between COF layers and produce COF nanosheets (CONs) suitable to be processable for different applications.We are especially interested in the development of photo and electroactive COFs for applications related with energy. In this communication we will comment on our previous results on 2D-COFs for charge storage and catalysis and  we will highlight our recent results on the development of COFs organic cathode materials with multiple redox sites (Figure) as efficient electrocatalysts for the oxygen reduction reaction (ORR).[10-14] 

 

 

Important benefits of these new COFs are that they are not only metal free, but also no additional
pyrolysis process has to be applied before its use. Instead, the electrocatalytic activity is a consequence of the specific electroactive
moieties selected for the design of the new COF electrocatalysts.

16:15 - 16:30
1B-T4
Liu, Kejun
Max Planck Institute of Microstructure Physics
A Highly Doped Quasi-2D Polypyrrole Film Synthesized on Concentrated Sulphuric Acid Surface
Liu, Kejun
Max Planck Institute of Microstructure Physics, DE
Authors
Kejun Liu a, b, Renhao Dong b, Xinliang Feng a, b
Affiliations
a, Max Planck Institute of Microstructure Physics, Max Planck Institute of Microstructure Physics, Weinberg 2, Halle, DE
b, Chair for Molecular Functional Materials, Center for Advancing Electronics Dresden, Faculty of Chemistry and Food Chemistry, Technische Universität Dresden, Germany, 01069 Dresde, Alemania, Dresde, DE
Abstract

Quasi-two-dimensional conjugated polymers (q2DCPs) consist of 2D layered structures formed by the assembly of linear conjugated polymer chains via non-covalent bonds. They attracted increasing attention in recent years due to their outstanding physical properties, such as 2D coherent charge transport, high electrical conductivity, and significant enhancement of thermoelectric power factors. Polypyrrole (PPy) is one of the most studied linear conjugated polymers due to its unique optical and electrical properties associated with broad applications. However, it has remained largely unexplored to develop structurally defined PPy-based q2DCPs, referred to as quasi-two-dimensional polypyrrole (q2DPPy) due to challenges in synthesis, such as the helical conformation of PPy chain, side reaction and insufficient doping. In this work, we demonstrate the synthesis of novel q2DPPy films through oxidation polymerization of pyrrole on a concentrated sulphuric acid surface. Aberration-corrected high-resolution transmission electron microscopy (AC-HRTEM), grazing-incidence wide-angle X-ray scattering (GIWAXS) and density functional based tight-binding (DFTB) calculation indicate that the q2DPPy film is formed by layered assembly of protonated quinoidal chains with fully stretched conformation. The pyrrole unit of q2DPPy presents a fully cationic form compensated by HSO4- with a theoretically maximum doping level of n(HSO4-)/n(Py+) ≈ 1:1. This unique chain conformation and high doping level lead to a narrow bandgap and significant light absorbance of the q2DPPy film in the near-infrared (NIR) region. Remarkably, the resulting q2DPPy film displays record-high mobility of 31.68 cm2V-1s-1 by time-resolved terahertz spectroscopy (TRTS). We believe that this work is of general interest to a broad range of readers in 2D materials, conjugated polymer materials, supramolecular chemistry and physical science. We hope that you will share our excitement about the scientific breakthrough achieved in the present work.

16:30 - 16:45
1B-T5
Pshenichnikov, Maxim S.
University of Groningen, The Netherlands
Double-wall nanotubes as quasi-2D molecular crystals
Pshenichnikov, Maxim S.
University of Groningen, The Netherlands, NL
Authors
Maxim S. Pshenichnikov a, Sundar Raj Krishnaswamy a, Björn Kriete a
Affiliations
a, Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 4, Groningen, NL
Abstract

The natural light-harvesting antennae of plants and photosynthetic bacteria are one of the most fascinating functional molecular nanoassemblies. Their unprecedented quantum efficiency relies on the strong coupling between thousands of densely packed chromophores giving rise to highly delocalized excitons which travels over long distances before reaching the reaction centre. However, the structural complexity of these systems leads to spectral congestion thereby blurring individual exciton transfer pathways that are vital to unravel for potential applications. Artificial model systems allow for better understanding of the structure-property relationship through reducing the complexity of natural light-harvesting complexes and disclosing the working principles to the basic elements.

Here we demonstrate a novel spectroscopic/microfluidics approach to deconvolute the supramolecular hierarchy and its connection to optical properties of a model system, multi-layered nanotubes [1-3]. They are based on the C8S3 molecules which self-assemble in an aqueous surrounding to a highly-ordered, concentric double-walled nanotubes (DWNTs) of 6/13 nm in inner/outer diameter and few micrometres in length. Each of these NTs can be considered as a quasi-2D molecular system (a plane wrapped into a tube) of strongly coupled molecules which results in highly delocalized and mobile excitonic states. We will presented a power platform of microfluidics, optical spectroscopy, and cryo-TEM, used to unravel the nature of exciton delocalization as well as exciton diffusion in DWNTs. We will also discuss the intermediate dynamical states of self-assembly via microfluidics manipulation of the structural hierarchy on the nanoscale via controlled alterations of individual sub-units of DWNT [4].

17:00 - 18:30
Poster session
20:00 - 22:00
Social dinner
 
Fri Sep 16 2022
09:55 - 10:00
nanoGe Introduction
Session 2A
Chair not set
10:00 - 10:30
2A-I1
Coronado, Eugenio
Universidad de Valencia - ICMol (Institute of Molecular Science)
Functional Magnetic Molecules in 2D Materials
Coronado, Eugenio
Universidad de Valencia - ICMol (Institute of Molecular Science), ES
Authors
Eugenio Coronado a
Affiliations
a, Universidad de Valencia - ICMol (Institute of Molecular Science), Catedrático José Beltrán Martinez 2, Paterna, ES
Abstract

Graphene and other 2D materials are almost exclusively based on inorganic lattices. Except for the chemical functionalization of the surface of the 2D material, molecules have been scarcely considered in this area. Here I will illustrate the role of molecular magnetism in this area by selecting some relevant examples:

1) Molecular 2D magnets. I will focus on the design of molecular 2D magnets that, in contrast to what happens with the inorganic 2D magnets, are chemically stable in open air, keeping their magnetic properties preserved upon functionalizing their surface with different organic molecules [1].

2) Smart molecular/2D heterostructures. I propose to create hybrid heterostructures by interfacing stimuli-responsive molecular systems with graphene and semiconducting transition metal dichalcogenides (MoS2 and WSe2). The aim is that of tuning the properties of the “all surface” 2D material via an active control of the hybrid interface. This concept will provide an entire new class of smart molecular/2D heterostructures, which may be at the origin of a novel generation of hybrid materials and devices of direct application in highly topical fields like electronics, spintronics and straintronics. As smart-molecular systems I will choose magnetic spin-crossover materials able to switch between two spin states upon the application of an external stimulus (temperature, light or pressure) [2]. This spin transition is always accompanied by a significant change of volume in the material (by ca. 10%), so it can generate strain in its surroundings. I will show that in these heterostructures the electronic properties of graphene and the optical photoluminescence of monolayers of semiconducting metal dichalcogenides can be switched by light or by varying the temperature due to the strain concomitant to the spin transition [3, 4].

10:30 - 11:00
2A-I2
Ecija, David
IMDEA-Nanociencia
Tailoring the magnetic anisotropy of mono- and di-nuclear lanthanide metal-organic networks by metal exchange
Ecija, David
IMDEA-Nanociencia, ES
Authors
David Ecija a
Affiliations
a, IMDEA-Nanociencia, Campus de Cantoblanco, 28049 Madrid, Spain
Abstract

Molecular magnetism is an emerging field with potential for technological applications as high-density information storage, quantum computing and spintronics [1]. Molecular systems based on lanthanides are especially promising due to the fundamental properties of lanthanides. Their strong spin-orbit coupling can lead to a high magnetic anisotropy while the strong localization of 4f states reduces the hybridization with surfaces increasing spin lifetimes [2]. Both, a high anisotropy and a large spin lifetime, are essential to increase the magnetic stability and to develop practical applications. Some lanthanide molecular magnet systems have already been reported, as the double-decker phthalocyanine family (LnPc2) [3,4], but up to now the magnetism of lanthanides metal-organic networks remains an unexplored field.

We performed pioneering investigations in this field preparing lanthanide-direct metal-organic networks using three molecular linkers: (i) benzene-1,4-dicarboxylic acid (TPA) coordinated with Dy on Cu(111) [5]; (ii) p-terphenyl-4,4-dicarboxylic acid (TDA) coordinated with Dy and Er on Cu(111) [5]; (iii) 4,4'-Di(4-pyridyl)biphenyl (DPBP) coordinated with Dy and Er on Au(111) [6]. The structural, electronic and magnetic properties were investigated by scanning probe microscopy (STM) and spectroscopy (STS), X-ray linear dichroism (XLD) and X-ray magnetic circular dichroism (XMCD). The experimental results were complemented by density functional theory (DFT) calculations and multiplet calculations. TPA and TDA linkers coordinate with lanthanides in almost square lattices with mononuclear metallic centers, and DPBP forms rhombic binuclear lattices. In both cases the network structure is preserved when the lanthanide atom is exchanged. However, the magnetic properties are drastically altered. The orientation of the easy axis of magnetization and the intensity of the magnetic anisotropy are strongly dependent on the metallic center and the molecular linker. Our results show that it is possible to tailor the magnetic properties of lanthanides by a proper choice of molecular linkers and metallic centers.

11:00 - 11:30
Coffee Break
11:30 - 12:00
2A-I3
Bonn, Mischa
Max Planck Institute for Polymer Research, Mainz
Conjugated organic frameworks with record charge carrier mobility
Bonn, Mischa
Max Planck Institute for Polymer Research, Mainz, DE

1. Personal details Prof. Dr. Mischa Bonn Max Planck Institute for Polymer Research Ackermannweg 10 D-55128 Mainz Male; born, 25/01/71, Nijmegen (NL), married +1. Nationality: Dutch (NL) 2. Education Undergraduate: University of Amsterdam; MSc in Physical Chemistry (highest honors), 10/05/93 Graduate: AMOLF / University of Eindhoven; PhD in Physical Chemistry, 18/12/96 Postdoctoral: Fritz Haber (Max Planck) Institut (Wolf/Ertl group), Berlin, Germany, 1997�1999 Postdoctoral: Columbia University (Heinz group) NY, USA, 1998-2001 (totaling ~6 months). 3. Appointments 4/2011-present Director at the Max Planck Institute for Polymer Research, Mainz, Germany 5/2013-present Honorary Professor (Chemistry Dept.) University of Mainz 6/2005�present Extraordinary Professor (Physics Dept.) University of Amsterdam 1/2004�3/2012 Group Leader at FOM-Institute for Atomic and Molecular Physics 1/2003�1/2004 Scientific Advisor at FOM-Institute for Plasma Physics �Rijnhuizen� 1/2003�9/2009 Associate professor (tenured) at Leiden University (Chemistry Dept.) 8/1999�12/2002 Assistant professor (fixed term) at Leiden University (Chemistry Dept.)

Authors
Mischa Bonn a, Shuai Fu a, Enquan Jin b, Hiroki Hanayama c, Wenhao Zheng a, Heng Zhang a, Lucia di Virgilio a, Akimitsu Narita a, c, Klaus Müllen a, Hai I. Wang a
Affiliations
a, Max Planck Institute for polymer Research, 55128 Mainz, Germany
b, Jilin University, Qianjin Street No.2699, Changchun, 130000, CN
c, Okinawa Institute of Science and Technology Graduate University, 1919-1 Tancha, Onna, JP
Abstract

Two-dimensional covalent organic frameworks (2D COFs) are crystalline porous polymers characterized by long-range order and well-defined open nanochannels. 2D COFs are promising for applications in electronics, catalysis, sensing, and energy storage. The development of highly conductive 2D COFs has remained challenging due to the finite π-conjugation along the 2D lattice and defects introduced by grain boundaries. Furthermore, the charge transport mechanism within the crystalline framework has remained elusive. We use time- and frequency-resolved terahertz spectroscopy to reveal intrinsically Drude-type band transport of charge carriers in semiconducting 2D COF thin films condensed by 1,3,5-tris(4-aminophenyl)benzene (TPB) and 1,3,5-triformylbenzene (TFB). The TPB–TFB COF thin films demonstrate high photoconductivity with an exceptionally long charge scattering time exceeding 70 fs at room temperature which resembles crystalline inorganic materials. This corresponds to a record charge carrier mobility of 165 ± 10 cm2 V–1 s–1, vastly outperforming that of the state-of-the-art conductive COFs. These results reveal TPB–TFB COF thin films as promising candidates for organic electronics and catalysis and provide insights into the rational design of highly crystalline porous materials for efficient and long-range charge transport.

12:00 - 12:30
2A-I4
Lozada-Hidalgo, Marcelo
The University of Manchester
Ion transport through two dimensional crystals
Lozada-Hidalgo, Marcelo
The University of Manchester, GB

Marcelo Lozada-Hidalgo is a Senior Lecturer (Associate Professor) and Royal Society University Research Fellow at the University of Manchester. His research group studies the permeability of two-dimensional materials to ions and gases. Key interests include ion selective membranes, proton transport processes, photo-assisted ion transport and isotope selectivity. He was awarded an M.Sc. in Physics by the National Autonomous University of Mexico (2012) and a PhD in Physics by The University of Manchester (2015). Since then, he built his independent research direction with support of an Early Career Fellowship by the Leverhulme Trust (2016); a Dame Kathleen Ollerenshaw Fellowship by the University of Manchester (UoM) (2019); a University Research Fellowship by the Royal Society (2020); and an ERC Starting Grant (2021).

Authors
Marcelo Lozada-Hidalgo a
Affiliations
a, The University of Manchester, Schuster Building, Manchester M13, UK, Manchester, GB
Abstract

The basal plane of graphene is impermeable to all atoms and molecules - even for helium, the smallest - at ambient conditions [1]. Nevertheless, it is permeable to thermal protons [2]. This talk will provide an overview of our investigation of permeation of protons and other small ions through new 2D materials [3-5], including the unexpectedly fast ion exchange properties of atomically thin clays and micas [6].

References

[1]  Bunch, J. S. et al. Impermeable atomic membranes from graphene sheets. Nano Lett. (2008)

[2]  Hu, S. et al. Proton transport through one-atom-thick crystals. Nature (2014).

[3]  Mogg, L. et al. Atomically-thin micas as proton conduting membranes. Nat. Nano  (2019).

[4]  Mogg. L. et al. Perfect proton selectivity in ion transport through two-dimensional crystals. Nat. Commun. (2019).

[5]  Griffin, E. et al. Proton and Li-Ion Permeation through Graphene with Eight-Atom-Ring Defects. ACS Nano (2020).

[6]  Y.-C. Zhou et al, Ion exchange in atomically thin clays and micas. Nat. Materials (2021).

12:30 - 14:30
Lunch
Session 2B
Chair not set
14:30 - 15:00
2B-I1
Kaiser, Ute
University of Ulm, DE
From Atomic-Resolution Imaging of Inorganic Two-Dimensional Materials to Molecular-Resolution Imaging of Organic Two-Dimensional Materials: Challenges and Solutions
Kaiser, Ute
University of Ulm, DE, DE
Authors
haoyuan qi a, baokun Liang a, Christopher Leist a, David Mücke a, Ute Kaiser a
Affiliations
a, University of Ulm, DE, Albert-Einstein-Allee 11, Ulm, DE
Abstract

In this study, we show that a detailed understanding of beam electron-sample interactions is required to achieve high-resolution structural imaging of two-dimensional materials. We start to derive basic understanding from atomically-resolved, time-dependent in-situ TEM imaging of inorganic two-dimensional (2D) transition metal dichalcogenides using the chromatic- and spherical-aberration-corrected low-voltage SALVE instrument operating in the voltage range between 80kV and 20kV [1-3]. We elucidate the accelerating-voltage-dependent formation of defects and find that elastic and inelastic interactions are strongly connected, resulting in a two-step interaction process. Density functional theory molecular dynamics shows that excitations in the electronic system can form vacancies through ballistic energy transfer at electron energies, which are much lower than the knock-on threshold for the ground state [4]. After the material under electron irradiation lost its ordered structure, the evaluation of the unordered structure is performed by developing a U-net-based neural network (NN).

The knowledge gained for the study of 2D inorganic materials we apply to the study of 2D polymers [5,6] and 2D metal-organic frameworks (MOFs) [7], where however atomically-resolved imaging is hindered due to much lower resilience against electron irradiation. We present key strategies to achieve higher resolution in high-resolution TEM images of imine-based 2D polymer films [8], which include the selection of the appropriate electron accelerating voltage [9]. When comparing the achievable resolution at 300kV, 200kV, 120kV and 80kV, we found that imaging at 120kV offers the highest resolution (1.9A). This resolution allowed even imaging the molecular nature of interstitial defects, which could be identified by means of quantum mechanical calculations [9]. The U-net-based NN developed for the analysis of inorganic amorphous 2D structures was also succsessfully applied on the evaluation of amorphous polymeric networks to understand the pore size distributions [9]. In addition, we show that even sub-Angstrom resolution can be achieved for hydrogen-free 2D BHT-Cu (BHT = benzenehexathiol) MOFs using the Cc/Cs-corrected SALVE microscope operating at 80 kV, resulting in imaging single atoms with high contrast.

Further, we study experimentally and computationally the role of different organometallic bonds and hydrogen content on electron radiation stability, using a group of four structurally similar Cu-based 2D MOFs with well-defined differences to allow for a direct comparison of hydrogen-containing and hydrogen-free MOFs, and of the presence of Cu - N, Cu - O and Cu - S chemical bonds. Trends in e-beam resilience among the 2D-MOFs found experimentally showed good agreement with ab initio molecular dynamics simulations of ejection cross-section.

15:00 - 15:30
2B-I2
Heine, Thomas
Two-dimensional topological polymers
Heine, Thomas

Thomas Heine graduated in physics from TU Dresden under the guidance of Gotthard Seifert, with research stages in Montréal (Dennis R. Salahub) and Exeter (Patrick Fowler). After postdoctoral stages in Bologna (Francesco Zerbetto) and Geneva (Jacques Weber) he obtained the venia legendi in Physical Chemistry at TU Dresden. In 2008 he was appointed as Associated Professor of Theoretical Physics/Theoretical Materials Science at Jacobs University and was promoted to Full Professor in 2011. From 2015-2018 he held the Chair of Theoretical Chemistry at University of Leipzig, Germany. Since 2018 is professor of theoretical chemistry at TU Dresden in joint appointment with Helmholtz-Center Dresden-Rossendorf. His research interests include molecular framework compounds, two-dimensional materials, theoretical spectroscopy, and the development of methods and software for materials science.

Authors
Thomas Heine a
Affiliations
a, Technical University (TU) Dresden, Mommsenstr. 13, Dresden, 1062, DE
Abstract

In the recent years, the synthesis of atomically precise framework materials such as metal-organic frameworks and covalent organic frameworks has resulted in first examples where the particular sub-class of two-dimensional (2D) polymers have both structural perfection and long-range crystalline order. Crystallinity imposes that lattice order effect emerge where properties, intrinsic to the lattice, reflect in the electronic and vibrational properties of the materials. 

I will highlight the importance of lattice effects on the chemical and physical properties of 2D polymers by starting from prototypical graphene towards materials with different underlying lattices, including honeycomb, square, kagome, and square-octagon lattices. Some of these lattices show correlated features such as flat bands and Dirac points, which result both in interesting physical phenomena, but are also opening the door for applications in catalysis. I will highlight the particular example of photocatalysis on honeycomb-kagome heterotriangulene 2D polymers and show how the interplay of molecular functionality and long-range order results in efficient metal-free non-toxic photocatalysts.

 

15:30 - 15:45
2B-T1
Gali, Sai Manoj
Laboratory for Chemistry of Novel Materials, University of Mons, Belgium
Tunable electronic structure of 2D-MOFs via molecular functionalization. A computational perspective
Gali, Sai Manoj
Laboratory for Chemistry of Novel Materials, University of Mons, Belgium, BE

Sai Manoj GALI, worked as a researcher and rocket engineer in the Indian Space Research Organization (ISRO): Satish Dhawan Space Centre, Sriharikota- India, during the period 2007-2012.

He received a Master degree (M.Sc) in 2014 by joining the European Erasmus Mundus Master in Functional Advanced Materials Engineering (FAME) between the University of Augsburg (Germany) and the University of Bordeaux (France).

He earned a PhD in Chemical Physics from the University of Bordeaux (France) in 2017, working in the group of organic electronics, under the supervision of Dr. Luca Muccioli and Dr. Frederic Castet. His PhD was focused on exploring the relation between the molecular structure, energetic fluctuations and micro-mechanical strains on the charge transport properties of organic electronic materials, through atomistic modeling.

Since November 2017, he is a research fellow at the Laboratory for Chemistry of Novel Materials (CMN): University of Mons under the guidance of Dr. David BELJONNE, with a focus on the theoretical & computational studies of opto-electronic and charge transport properties of pristine, defective and functionalized two-dimensional (2D) materials, such as TMDCs, 2D-COFs, MXenes, Graphene and Graphene oxides, combing various computational tools ranging from quantum-chemical calculations and tight-binding models to atomistic simulations employing ab-initio and force-field molecular dynamics simulations.

Authors
Sai Manoj Gali a, Petru Apostol b, Alexandru Vlad b, David Beljonne a
Affiliations
a, Laboratory for Chemistry of Novel Materials, University of Mons, Belgium, Place du Parc, 20, Mons, BE
b, Division of Molecular Chemistry, Materials and Catalysis, Institute of Condensed Matter and Nanosciences, Université Catholique de Louvain ET. D'UTIL. PUB, 6000 Charleroi, Bélgica, Charleroi, BE
Abstract

Ni3(hexaiminotriphenylene)2 aka Ni3(HITP)2 is a p-type semiconducting two-dimensional (2D) metal organic framework (MOF) analogous to graphene, with high ohmic conductivity of the order of ≈ 40 Scm-1, as reported by Sheberla et al[1]. Subsequently, a copper based conductive Cu3(HITP)2 was reported with potential application in gas sensing[2]. Previous theoretical investigations indicate that these MOFs are metallic in bulk, whereas in their monolayers forms only Ni3(HITP)2 is semiconducting but with a narrow band gap[3,4].  Herein, inspired by the Band Structure Engineering (BSE) deployed for OSCs and based on the recent advancements in truxene based semiconductors[5-6], we consider different variants of Ni3(hexaimidetriazatruxene)2, Ni3(HITAT)2 aka MOF1, analogues to Ni3(HITP). MOF1 is then functionalized by either: (i) substituting the ‘NH’ groups with sulfur atom[5,6] resulting in Ni3(HITTT)2 aka MOF2, (ii) using truxenone as building block resulting in Ni3(HITXN)2 aka MOF3 and (iii) grafting cyano groups resulting in Ni3(HITCT)2 aka MOF4. The building blocks of these 2D-MOFs have been carefully selected as they can potentially improve the p-type transport, as expected in MOF2 when compared to MOF1, whereas the electron poor units in MOF3 and MOF4 should turn the MOFs into n-type materials[7-8] while being prone to act as acceptors for metal-ion batteries. The role of molecular functionalization in these 2D-MOFs is discussed in terms of the variation in the bandwidths, bandgaps, in-plane effective masses, ionization potential and electron affinity.

15:45 - 16:00
2B-T2
Wang, Mingchao
Technische Universität Dresden
Electronic Properties of Metal-Phthalocyanine-Based 2D conjugated COFs
Wang, Mingchao
Technische Universität Dresden, DE
Authors
Mingchao Wang a, Shengqiang Zhou b, Mischa Bonn c, Thomas Heine a, Enrique Cánovas c, d, Renhao Dong a, Xinliang Feng a
Affiliations
a, Technische Universität Dresden, Hallwachsstraße, 3, Dresden, DE
b, Helmholtz-Zentrum Dresden-Rossendorf, PO Box 510119, Dresden, 01314, DE
c, Max Planck Institute for polymer Research, 55128 Mainz, Germany
d, Instituto Madrileño de Estudios Avanzados en Nanociencia (IMDEA-Nanociencia), c/Faraday 9, Cantoblanco, 28049, Madrid
Abstract

Two-dimensional conjugated covalent organic frameworks (2D c-COFs) are emerging as a unique class of semiconducting 2D polymers for (opto-)electronics and energy devices. However, understanding the intricate interplay between the chemical structure and charge transport remains a challenge.[1,2] We have demonstrated two metal−phthalocyanine-based pyrazine-linked 2D c-COFs (termed as MPc-pz COF, M = Cu or Zn) as p-type semiconductors with a band gap of ∼1.2 eV and intrinsic charge mobility up to ∼5 cm2/(Vs).[3] The combination of Hall effect measurements, Terahertz spectroscopy, and density functional theory calculated electronic band structures provide a rational approach on how to assess structure-/doping-electronic property relationships.[2,3] The results reveal that varying metal center from Cu to Zn has a negligible effect on the charge transport behaviors. After reversible p-type doping with I2, the doping-defined 2D c-COF displays enhanced conductivity by 3 orders of magnitude, due to the elevated carrier concentration.[4] Remarkably, charge mobility also increased upon doping, which can be traced to increased scattering time for free charge carriers, indicating that scattering mechanisms limiting the mobility are mitigated by doping. These works provide a guideline on how to assess the structure-electronic property relationships in 2D c-COFs semiconductors and highlight their potential in organic (opto-)electronic devices.

16:00 - 16:15
2B-T3
Mañas-Valero, Samuel
Universidad de Valencia - ICMol (Institute of Molecular Science)
Magnetic and Electronic Properties of Two-Dimensional Metal-Organic Frameworks
Mañas-Valero, Samuel
Universidad de Valencia - ICMol (Institute of Molecular Science), ES
Authors
Samuel Mañas-Valero a, Javier López-Cabrelles a, Guillermo Mínguez-Espargallas a, Eugenio Coronado a
Affiliations
a, Universidad de Valencia - ICMol (Institute of Molecular Science), Catedrático José Beltrán Martinez 2, Paterna, ES
Abstract

Magnetic two-dimensional (2D) materials have emerged recently with examples of inorganic monolayers, like CrI3 [1] or CrSBr [2].

In this work,[3-5] we explore the magnetic properties of new 2D metal-organic frameworks (MOFs). In particular, we take advantage of layered molecular magnets since, thanks to the chemical design, it is feasible to bring new magnetic scenarios as well as to overcome the present instabilities of 2D magnetic materials. We develop a pre-synthetic method based on coordination chemistry that affords the isolation of crystalline molecular monolayers. The concept is illustrated using layered coordination polymers formed by reacting various benzimidazole derivatives with ferrocene. By the election of the proper ligand and the metal source, it is possible to tune the surface properties as well as the magnetism. Moreover, the magnetic order of the flakes is probed by its integration into membranes since phase transitions can be probed mechanically via the temperature-dependent resonance frequency and quality factor of the thin-membrane [6].

In addition, we recosnider the electrical characterization of the two-dimensional MOF M3(THT)2(NH4)3, (M = Fe, Ni, Cu, Co; THT, 2,3,6,7,10,11-triphenylenehexathiol),[7] observing that some claimed metallic phases[8] may be, indeed, higly insulating ones.

Overall, we detect the magnetic order in new magnetic 2D molecular materials and reconsider their electronic characterization. The results pave the way for studying phase transitions in the 2D limit in other metal-organic frameworks.
 

16:15 - 16:30
2B-T4
Pastukhova, Nadiia
University of Nova Gorica
Photoexcited charge mobility in quasi two-dimensional polyacetylene
Pastukhova, Nadiia
University of Nova Gorica, SI
Authors
Nadiia Pastukhova a, Kejun Liu b, Renhao Dong b, Gvido Bratina a, Xinliang Feng b, Egon Pavlica a
Affiliations
a, Laboratory of Organic Matter Physics, University of Nova Gorica, Slovenia, Vipavska cesta, SI
b, Chair for Molecular Functional Materials, Center for Advancing Electronics Dresden, Faculty of Chemistry and Food Chemistry, Technische Universität Dresden, Germany, 01069 Dresde, Alemania, Dresde, DE
Abstract

Two-dimensional conjugated polymers (2DCPs) have been described and recognised as crystalline, one- to two-layer polymer nanosheets prepared by 2D covalent polymerization exhibiting strong in-plane π-electron delocalization with two orthogonal directions and weak out-of-plane π-π stacking.[1,2] The extension of polymer dimensionality into two dimensions improves the alignment of individual polymer sheets and overcomes the limitations associated with charge carrier hopping between polymer chains in one-dimensional and crosslinked polymers.[3] Compared to other two-dimensional materials such as graphene or transition metal dichalcogenides, 2DCPs offer a high degree of flexibility in chemical design and are compatible with liquid-based processing methods. Various 2DCPs have been synthesised by surfactant monolayer-assisted interfacial synthesis (SMAIS).[5]

Of particular interest is the photoresponse of these materials due to their tunable properties, such as bandgap and associated wavelength-dependent photoexcitation, which enables a wide range of applications in optoelectronic devices. Using time-of-flight photoconductivity (TOF-PC) measurements [4], we investigate the charge transport properties of 2D polyacetylene prepared by SMAIS method. We preform TOF-PC measurement of 2D polyacetylene using a focused nanosecond pulse laser at 325 nm and electrode separation of 250 µm. From the bias polarity and time duration of the photocurrent, we can determine the polarity, velocity and mobility of photoexcited charge carriers as a function of applied bias voltage and excitation wavelength. Using excitation at 325 m, we observed an electron mobility in the range of 150 cmV-1 s-1, which is in the realm of most advances small-molecule single-crystal organic semiconductors and almost an order of magnitude higher than linear polymeric semiconductors.

16:30 - 16:45
2B-T5
Balos, Vasileios
IMDEA-Nanociencia
Electrical characterization of organic 2D materials by THz time-domain spectroscopy
Balos, Vasileios
IMDEA-Nanociencia, ES
Authors
Vasileios Balos a, Segio Revuelta a, Victor Vega a, Marco Ballabio a, Enrique Cánovas a
Affiliations
a, IMDEA Nanoscience, C/faraday, 9, Madrid, 28049, Madrid, ES
Abstract

In this work we introduce THz time-domain spectroscopy (THz-TDS) as a powerful non-contact tool for the characterization of the conductivity of metallic and semiconducting organic 2D crystalline materials. In a conventional THz-TDS experiment, a freely propagating ~1THz bandwidth reference pulse which is transmitted through air (or through a bare substrate transparent to THz radiation) is compared with a pulse transmitted through a self-standing sample (or a sample deposited onto the substrate). As the THz pulse is measured in the time domain, both, the amplitude and phase changes induced by the sample can be recorded; this enables retrieving the frequency-resolved complex conductivity. Modelling the later with electrical conduction models, allows accessing important key electric parameters as the averaged scattering rate and the plasma frequency from which, carrier density and charge carrier mobility could be inferred [1].

As a demonstration of the capabilities of THz-TDS, we present here several examples of studies of conductivity in 2D-based crystalline semiconducting and metallic MOF and COF materials. In a first example, we show how localization, induced by grain boundaries in polycrystals, modifies long-range charge transport in a semiconducting sample; as a second example we show how the interplane distance between 2D-MOF layers dramatically modifies the monitored conductivity. Finally, correlations between THz-TDS characterization and conventional 2- and 4-probe methods are highlighted.

16:45 - 17:00
2B-T6
Boix Constant, Carla
Universidad de Valencia - ICMol (Institute of Molecular Science)
Interplay between spin-crossover and strain in hybrid inorganic/molecular van der Waals heterostructures.
Boix Constant, Carla
Universidad de Valencia - ICMol (Institute of Molecular Science), ES
Authors
Carla Boix Constant a, Samuel Mañas a, Eugenio Coronado a
Affiliations
a, Universidad de Valencia - ICMol (Institute of Molecular Science), Catedrático José Beltrán Martinez 2, Paterna, ES
Abstract

Van der Waals heterostructures (vdWHs) provide the possibility of engineering new materials with emergent functionalities that are not accessible in another way. These heterostructures are formed by assembling layers of different materials used as building blocks. Beyond inorganic 2D crystals, layered molecular materials remain still rather unexplored, with only few examples regarding their isolation as atomically thin layers. Here, the family of van der Waals heterostructures is enlarged by introducing a molecular building block able to produce strain: the so-called spin-crossover (SCO). In these metal–organic materials, a spin transition can be induced by applying external stimuli like light, temperature, pressure, or an electric field. In particular, smart vdWHs are prepared in which the electronic and optical properties of the 2D material (graphene and WSe2) are clearly switched by the strain concomitant to the spin transition. These molecular/inorganic vdWHs represent the deterministic incorporation of bistable molecular layers with other 2D crystals of interest in the emergent fields of straintronics and band engineering in low-dimensional materials.

17:00 - 17:05
Closing
 
Posters
Renhao Dong, Peng Han, Himani Arora, Marco Ballabio, Melike Karakus, Zhe Zhang, Chandra Shekhar, Peter Adler, Petko St. Petkov, Artur Erbe, Stefan C. B. Mannsfeld, Claudia Felser, Thomas Heine, Mischa Bonn, Xinliang Feng, Enrique Cánovas
High-Mobility Band-Like Charge Transport in a Semiconducting Two-Dimensional Fe2THT3 MOF
Sandra Martínez Estévez, Enrique Cánovas Díaz, Mariela Menghini, Ignacio Figueruelo Campanero, María Acebrón Rodicio, Julia García Pérez, Daniel Granados Ruiz, Felix Raso Alonso, Grzegorz Luka, Luca Callerado, Francois Couedö, Hansjoerg Scherer, Alienis Sadak, Thomas Heine, Massimo Ortolano, Renhao Dong, Xinliang Feng
Two Dimensional Lattices of Covalent- and Metal-Organic Frameworks for the Quantum Hall Resistance Standard
Shuai Fu, Enquan Jin, Donglin Jiang, Hai Wang
Module-Patterned Polymerization towards 2D sp2-Carbon Covalent Organic Frameworks and Their Charge Transport Properties
yamei liu, xinliang feng
Thiophene‐Rich 2D sp2‐Carbon‐Linked Semiconducting Conjugated Polymers
Wenhao Zheng, Alexander Tries, Akimitsu Narita, Mischa Bonn, Hai Wang
Charge Transport and Exciton Formation in Graphene Nanoribbons
Lukas Sporrer, Renhao Dong, Xinliang Feng
Synthesis of a highly conductive semiquinone based 2D conductive MOF with increased out-of-plane charge transport
Albrecht L. Waentig, Mino Borrelli, Dominik L. Pastoetter, Xinliang Feng
Two-Dimensional Conjugated Polymers for the Photoelectrochemical Oxidation of Nitrogen

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