Dynamics of Photoinduced Charge Carriers in Metal-Halide Perovskites

TL;DR

This study investigates charge-carrier dynamics in CsPbBr3 perovskites using time-resolved measurements, revealing trap-dominated recombination and ultra-long lifetimes, which have implications for diverse optoelectronic applications.

Contribution

It provides a detailed analysis of recombination mechanisms in CsPbBr3, emphasizing the importance of injection-dependent measurements and highlighting charge trapping effects.

Findings

Charge trapping dominates recombination in CsPbBr3.

Ultra-long charge-carrier lifetimes observed due to trapping.

Injection-dependent measurements are essential for identifying recombination mechanisms.

Abstract

The measurement and description of the charge-carrier lifetime (tauc) is crucial for the wide-ranging applications of lead-halide perovskites. We present time-resolved microwave-detected photoconductivity decay (TRMCD) measurements and a detailed analysis of the possible recombination mechanisms including trap-assisted, radiative, and Auger recombination. We prove that performing injection-dependent measurement is crucial in identifying the recombination mechanism. We present temperature and injection level dependent measurements in CsPbBr_3, which is an inorganic lead-halide perovskite. In this material, we observe the dominance of charge-carrier trapping, which results in ultra-long charge-carrier lifetimes. Although charge trapping can limit the effectiveness of materials in photovoltaic applications, it also offers significant advantages for various alternative uses, including delayed and persistent photodetection, charge-trap memory, afterglow light-emitting diodes, quantum information storage, and photocatalytic activity.