Abstract

Anharmonic crystal lattice dynamics have been observed in lead halide perovskites on picosecond timescales. Here, we report that the soft nature of the perovskite crystal lattice gives rise to dynamic fluctuations in the electronic properties of excited states. We use linear polarization selective transient absorption spectroscopy to study the charge carrier relaxation dynamics in lead-halide perovskite films and nanocrystals. We find that photo-excited charge carriers maintain an initial polarization anisotropy for several picoseconds, independent of crystallite size and composition, and well beyond the reported timescales of carrier scattering. First-principles calculations find intrinsic anisotropies in the transition dipole moment, which depend on the orientation of light polarization and the polar distortion of the local crystal lattice. Lattice dynamics are imprinted in the optical transitions and anisotropies arise on the time-scales of structural motion. The strong coupling between electronic states and structural dynamics requires a unique interpretation of recombination and transport mechanisms.

Details

Title
Long-lived polarization memory in the electronic states of lead-halide perovskites from local structural dynamics
Author
Rivett, Jasmine P H 1 ; Tan, Liang Z 2   VIAFID ORCID Logo  ; Price, Michael B 1 ; Bourelle, Sean A 1 ; Nathaniel J L K Davis 3 ; Xiao, James 1 ; Zou, Yatao 4 ; Middleton, Rox 5   VIAFID ORCID Logo  ; Sun, Baoquan 4 ; Rappe, Andrew M 2   VIAFID ORCID Logo  ; Credgington, Dan 1   VIAFID ORCID Logo  ; Deschler, Felix 1   VIAFID ORCID Logo 

 Cavendish Laboratory, University of Cambridge, Cambridge, UK 
 Department of Chemistry, University of Pennsylvania, Philadelphia, PA, USA 
 School of Chemical and Physical Sciences, Victoria University of Wellington, Wellington, New Zealand 
 Institute of Functional Nano & Soft Materials (FUNSOM), Soochow University, Suzhou, People’s Republic of China 
 Department of Chemistry, University of Cambridge, Cambridge, UK 
Pages
1-8
Publication year
2018
Publication date
Aug 2018
Publisher
Nature Publishing Group
e-ISSN
20411723
Source type
Scholarly Journal
Language of publication
English
ProQuest document ID
2097572916
Copyright
© 2018. This work is published under http://creativecommons.org/licenses/by/4.0/ (the “License”). Notwithstanding the ProQuest Terms and Conditions, you may use this content in accordance with the terms of the License.