Deriving mobility-lifetime products in halide perovskite films from spectrally- and time-resolved photoluminescence

TL;DR

This paper introduces a novel method using transient photoluminescence spectroscopy to simultaneously determine charge-carrier mobility, lifetime, and diffusion length in halide perovskite films, addressing inconsistencies in existing measurements.

Contribution

It presents a unified approach for extracting key electronic parameters from a single spectroscopic technique, improving accuracy and consistency in characterizing perovskite materials.

Findings

Successfully derived mobility and lifetime from photoluminescence decay.

Quantified diffusion length and its voltage dependence.

Provided a more consistent measurement method for perovskite parameters.

Abstract

Lead-halide perovskites are semiconductor materials with attractive properties for photovoltaic and other optoelectronic applications. However, determining crucial electronic material parameters, such as charge-carrier mobility and lifetime, is plagued by a wide range of reported values and inconsistencies caused by interpreting and reporting data originating from different measurement techniques. In this paper, we propose a method for the simultaneous determination of mobility and lifetime using only one technique: transient photoluminescence spectroscopy. By measuring and simulating the decay of the photoluminescence intensity and the redshift of the photoluminescence peak as a function of time after the laser pulse, we extract the mobility, lifetime, and diffusion length of halide perovskite films. With a voltage-dependent steady-state photoluminescence measurement on a cell, we relate the diffusion length to the external voltage and quantify its value at the maximum power point.