Robust Bloch character at the band edges of hybrid halide perovskites

TL;DR

This paper introduces a spectral density method to compare electronic structures of high- and low-symmetry phases of halide perovskites, revealing robust features at the band edges despite structural disorder.

Contribution

It presents a novel spectral density approach to analyze and compare band structures across different phases of halide perovskites, accounting for disorder effects.

Findings

Band edge states are robust against structural disorder.

Spectral density technique effectively reduces supercell band structures.

Comparison reveals minimal changes at the band edges across phases.

Abstract

The high-symmetry pseudocubic init cell is often used for modelling the electronic structure of halide perovskites. However, direct comparison of the band structure with more realistic low-symmetry phases is impeded by the zone folding. We utilize a spectral density technique in order to reduce the supercell band structure to a common Bloch basis. This allows us to compare the electronic structure of high- and low-symmetry phases as well as investigate effects of structural and compositional disorder on states near to the band edges that govern transport, dissociation and recombination of optical excitations.