Exciton-polaron dynamics in lead halide perovskite nanocrystals

Abstract

Exciton-polaron dynamics in lead halide perovskite nanocrystalsHelene Seiler a, b, Daniela Zahn a, Victoria C.A. Taylor a, Maryna I. Bodnarchuk c, Yoav W. Windsor a, d, Maksym Kovalenko e, c, Ralph Ernstorfer a, da Fritz Haber Institute of the Max Planck Society, Department of Physical Chemistry, 14195 Berlin, Germanyb Freie Universität Berlin, Arnimallee 14, Berlin, Germanyc Laboratory for Thin Films and Photovoltaics, Empa – Swiss Federal Laboratories for Materials Science and Technology, CH-8600 Dübendorf, Switzerlandd Technische Universität Berlin, Straße des 17. Juni 124, Berlin, Germanye ETHZMaterials for Sustainable Development Conference (MATSUS)Proceedings of MATSUS Spring 2024 Conference (MATSUS24)#PeroQuant24 - Halide perovskites for quantum technologiesBarcelona, Spain, 2024 March 4th - 8thOrganizers: Simon Boehme, Sascha Feldmann and Maksym KovalenkoInvited Speaker, Helene Seiler, presentation 090DOI: https://doi.org/10.29363/nanoge.matsus.2024.090Publication date: 18th December 2023Lead halide perovskites have attracted tremendous attention, initially for their performance in thin film photovoltaics, and more recently for a variety of remarkable optical properties. Defect tolerance through polaron formation within the ionic lattice is a key aspect of these materials. In recent studies [1,2], some of us have applied two-dimensional electronic spectroscopy (2DES) to probe the timescale and amplitude of the electronic gap correlations in lead halide perovskite nanocrystals via homogeneous lineshape dynamics. The 2DES data reveal irreversible, diffusive dynamics that are consistent with liquid-like structural dynamics on the 100 femtosecond timescale. These dynamics were assigned to the optical signature of polaron formation, the conceptual solid-state analogue of solvation. To complement the 2DES data, we have employed the method of femtosecond electron diffraction (FED) to directly measure the sub-picosecond lattice dynamics of weakly confined CsPbBr3 nanocrystals following above-gap photoexcitation. The data reveal a light-induced structural distortion appearing on a time scale varying between 380 and 1200 fs depending on the excitation fluence. We attribute these dynamics to the effect of exciton–polarons on the lattice and the slower dynamics at high fluences to slower sub-picosecond hot-carrier cooling, which slows down the establishment of the exciton–polaron population. Further analysis and simulations show that the distortion is consistent with motions of the [PbBr3]− octahedral ionic cage, and closest agreement with the data is obtained for Pb–Br bond lengthening. Together, the 2DES and FED data offer a unique and complementary view of exciton-polaron dynamics in lead halide perovskite nanocrystals. References:[1] Seiler, H., Palato, S., Sonnichsen, C. et al. Two-dimensional electronic spectroscopy reveals liquid-like lineshape dynamics in CsPbI3 perovskite nanocrystals. Nat Commun 10, 4962 (2019).[2] Patrick Brosseau, Arnab Ghosh, Helene Seiler, Dallas Strandell, Patanjali Kambhampati; Exciton–polaron interactions in metal halide perovskite nanocrystals revealed via two-dimensional electronic spectroscopy. J. Chem. Phys. 14 November 2023; 159 (18): 184711.© FUNDACIO DE LA COMUNITAT VALENCIANA SCITOnanoGe 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.nanoGe Fall MeetingnanoGe Fall Meeting (NFM) is a multiple symposia conference celebrated yearly and 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.nanoGe Spring MeetingThis conference is a unique series of symposia focused on advanced materials preparation and fundamental properties and their applications, in fields such as renewable energy (photovoltaics, batteries), lighting, semiconductor quantum dots, 2-D materials synthesis and semiconductors fundamentals, bioimaging, etc.International Conference on Hybrid and Organic PhotovoltaicsInternational 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 OptoelectronicsThe 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.International Conference on Perovskite Thin Film Photovoltaics Perovskite Photonics and OptoelectronicsThe 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.