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

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

SUBMITTER: Rivett JPH 

PROVIDER: S-EPMC6117347 | biostudies-literature | 2018 Aug

REPOSITORIES: biostudies-literature