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Long-lived polarization memory in the electronic states of lead-halide perovskites from local structural dynamics.

Published version
Peer-reviewed

Type

Article

Change log

Authors

Rivett, Jasmine PH 
Price, Michael B 
Bourelle, Sean A 
Davis, Nathaniel JLK 

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.

Description

Keywords

0306 Physical Chemistry (incl. Structural)

Journal Title

Nat Commun

Conference Name

Journal ISSN

2041-1723
2041-1723

Volume Title

9

Publisher

Springer Science and Business Media LLC
Sponsorship
EPSRC (1360817)
EPSRC (1494744)
Engineering and Physical Sciences Research Council (EP/G037221/1)
Engineering and Physical Sciences Research Council (EP/L015978/1)
EPSRC (1804146)