Low-frequency Vibrational Dynamics as a Probe of Local Structure in Hybrid Perovskite Materials
Kacper Drużbicki b
a Materials Physics Center, CSIC-UPV/EHU, 20018 Donostia, San Sebastian, Spain
b Polish Academy of Sciences, Centre of Molecular and Macromolecular Studies, 90-363 Lodz, Poland
Proceedings of Online Conference on Atomic-level Characterisation of Hybrid Perovskites (HPATOM2)
Online, Spain, 2022 February 2nd - 3rd
Organizers: Michael Hope and Eve Mozur
Invited Speaker, Kacper Drużbicki, presentation 019
DOI: https://doi.org/10.29363/nanoge.hpatom.2022.019
Publication date: 30th October 2021

Understanding the atomic structure and dynamics of Organometal Halide Perovskites (OHPs) is critical to rationalize their exceptional photovoltaic performance.[1] OHPs emerge as soft non-canonical solids, characterized by coherent photo-carrier transport typical of crystalline semiconductors, yet a dielectric response and atomic dynamics typical of liquids. Such a duality stems from a subtle balance between the flexibility of inorganic framework, the associated guest-host interactions, and thermally activated dynamics of the intercalated cations. Consequently, the resulting spatially limited atom ordering, intrinsic crystal twinning tendency, and high-propensity to form domains of different origin pose significant challenges to crystallography, and even in the case of quintessential OHPs, including MAPbI3 or MAPbBr3, their structural properties remain vague.

Regardless average structure revealed by Bragg diffraction, there is a need for atomic-resolution local structural information, where solid-state Nuclear Magnetic Resonance (ssNMR) techniques appear as methods of choice,[2] yet, being particularly challenging at cryogenic conditions. In this regard, high-resolution terahertz spectroscopic measurements using photons and neutrons[3-5] can be further considered as a complementary and powerful alternative. This talk will provide a brief overview of the application of high-resolution Inelastic Neutron Scattering (INS) supported by ab initio modeling to interrogate local structure in the archetypal iodoplumbate-OHPs, with MAPbI3 and FAPbI3, along with the mixed-cation perovskites, MA1-xFAxPbI3, given as prime examples.

© FUNDACIO DE LA COMUNITAT VALENCIANA SCITO
We use our own and third party cookies for analysing and measuring usage of our website to improve our services. If you continue browsing, we consider accepting its use. You can check our Cookies Policy in which you will also find how to configure your web browser for the use of cookies. More info