# Effect of disorder on transport properties in a tight-binding model for lead halide perovskites

## TL;DR

This study investigates how disorder affects electronic transport in lead halide perovskites using a tight-binding model, revealing that these materials remain largely delocalized despite disorder, with implications for their photovoltaic performance.

## Contribution

It provides a detailed analysis of disorder effects on electronic states in lead halide perovskites, highlighting their robustness and the impact of halide mixing on localization.

## Key findings

- Disorder does not induce strong localization in lead halide perovskites.
- Mixed-halide materials tend to have more localized electronic states.
- Electronic states remain highly delocalized despite inherent disorder.

## Abstract

The hybrid organic-inorganic lead halide perovskite materials have emerged as remarkable materials for photovoltaic applications. Their strengths include good electric transport properties in spite of the disorder inherent in them. Motivated by this observation, we analyze the effects of disorder on the energy eigenstates of a tight-binding model of these materials. In particular, we analyze the spatial extension of the energy eigenstates, which is quantified by the inverse participation ratio. This parameter exhibits a tendency, and possibly a phase transition, to localization as the on-site energy disorder strength is increased. However, we argue that the disorder in the lead halide perovskites corresponds to a point in the regime of highly delocalized states. Our results also suggest that the electronic states of mixed-halide materials tend to be more localized than those of pure materials, which suggests a weaker tendency to form extended bonding states in the mixed-halide materials and is therefore not favourable for halide mixing.