Are Shockley-Read-Hall and ABC models valid for lead halide perovskites?

Abstract

Metal halide perovskites are an important class of emerging semiconductors. Their charge dynamics is poorly understood due to limited knowledge of defect physics and charge recombination mechanisms. Nevertheless, classical ABC and Shockley-Read-Hall (SRH) models are ubiquitously applied to perovskites without considering their validity. Herein, an advanced technique mapping photoluminescence quantum yield (PLQY) as a function of both the excitation pulse energy and repetition frequency is developed and employed to examine the validity of these models. While ABC and SRH fail to explain the charge dynamics in a broad range of conditions, the addition of Auger recombination and trapping to the SRH model enables a quantitative fitting of PLQY maps and low-power PL decay kinetics, and extracting trap concentrations and efficacies. Higher-power PL kinetics requires the inclusion of additional non-linear processes. The PLQY mapping developed herein is suitable for a comprehensive testing of theories and is applicable to any semiconductor.