Proceedings of nanoGe September Meeting 2017 (NFM17)
Publication date: 20th June 2016
Colloidal perovskite nanocrystals (PNCs) of all-inorganic materials (CsPbX3, X = Cl-, Br- and I-) have emerged as a promising new class of nanomaterials due to their exceptional optoelectronic properties. Even as-synthesized and unpurified, these materials can reach a photoluminescence quantum yield (PLQY) of up to 90%, exhibit tunable and narrow emission bandwidths in the visible spectrum and have a high tolerance against defects. The origins of these outstanding properties are however still largely unknown, especially when compared to analogous semiconductor nanocrystals such as lead chalcogenides, for which it is still difficult to reach a PLQY beyond 20%.
To get a better understanding of the properties of CsPbX3 PNCs, we construct cesium lead halide models while taking into account experimental conditions. We perform density functional theory calculations on these models and we analyze the effect of size, shape and halide composition on the electronic structure. Our models are nominally free of trap states and exhibit both a clear quantum confinement and halide effect. We show that the electronic structure is only affected slightly upon removal of ligands from the surface, indicating that these PNCs are unexpectedly robust towards degradation of the nanocrystal.
Lastly, we use computational tools to investigate excitation of PNCs by photons with a greater energy than the band gap. We first perform ab initio molecular dynamics calculations on our PNC models and follow them up with excitation dynamics calculations. Using these calculations, we analyze properties such as the cooling rate of excited electrons and their holes, the coupling between states that are relevant for excited-state processes and the dephasing time of an excited system. We perform these calculations on PNC models of different sizes and materials composition and discuss the trends between these different models.
nanoGe is a prestigious brand of successful science conferences that are developed along the year in different areas of the world since 2009. Our worldwide conferences cover cutting-edge materials topics like perovskite solar cells, photovoltaics, optoelectronics, solar fuel conversion, surface science, catalysis and two-dimensional materials, among many others.
Previously nanoGe Spring Meeting (NSM) and nanoGe Fall Meeting (NFM), MATSUS is a multiple symposia conference focused on a broad set of topics of advanced materials preparation, their fundamental properties, and their applications, in fields such as renewable energy, photovoltaics, lighting, semiconductor quantum dots, 2-D materials synthesis, charge carriers dynamics, microscopy and spectroscopy semiconductors fundamentals, etc.
International Conference on Hybrid and Organic Photovoltaics
International Conference on Hybrid and Organic Photovoltaics (HOPV) is celebrated yearly in May. The main topics are the development, function and modeling of materials and devices for hybrid and organic solar cells. The field is now dominated by perovskite solar cells but also other hybrid technologies, as organic solar cells, quantum dot solar cells, and dye-sensitized solar cells and their integration into devices for photoelectrochemical solar fuel production.
Asia-Pacific International Conference on Perovskite, Organic Photovoltaics and Optoelectronics
The main topics of the Asia-Pacific International Conference on Perovskite, Organic Photovoltaics and Optoelectronics (IPEROP) are discussed every year in Asia-Pacific for gathering the recent advances in the fields of material preparation, modeling and fabrication of perovskite and hybrid and organic materials. Photovoltaic devices are analyzed from fundamental physics and materials properties to a broad set of applications. The conference also covers the developments of perovskite optoelectronics, including light-emitting diodes, lasers, optical devices, nanophotonics, nonlinear optical properties, colloidal nanostructures, photophysics and light-matter coupling.
The International Conference on Perovskite Thin Film Photovoltaics Perovskite Photonics and Optoelectronics (NIPHO) is the best place to hear the latest developments in perovskite solar cells as well as on recent advances in the fields of perovskite light-emitting diodes, lasers, optical devices, nanophotonics, nonlinear optical properties, colloidal nanostructures, photophysics and light-matter coupling.