Characterization of trap states in perovskite films by simultaneous fitting of steady-state and transient photoluminescence measurements

Date

2018-08-16

Authors

Fu, Xiao
Weber, Klaus
White, Thomas

Journal Title

Journal ISSN

Volume Title

Publisher

American Institute of Physics

Abstract

Understanding carrier recombination mechanisms and quantifying recombination dynamics are key to improving the performance of state-of-the-art perovskite solar cells. Here we present method to quantify the quality of perovskite thin films using a combination of steady-state and transient photoluminescence measurements. The combined experimental data sets are fitted using a single, general recombination model, from which detailed trap and recombination parameters can be extracted, and the accuracy of the fitted values estimated. This approach expands the application of photoluminescence measurements to include quantitative evaluation of the most relevant defect characteristics, including trap density, energy level and carrier capture coefficients. We apply this approach to compare perovskite films of the widely-studied methyl-ammonium lead iodide (MAPbI3) with the high performance quadruple-cation, mixed-halide composition Cs0.07Rb0.03(FA0.85MA0.15)0.9Pb(I0.85Br0.15)3. Our quantitative analysis of trap properties in these perovskite films suggests that the superior performance of the quadruple cation films may be due to a greatly reduced electron capture coefficient, rather than a significant reduction in the trap density.

Description

Keywords

Perovskite solar cells, Photovoltaics

Citation

Source

Journal of Applied Physics

Type

Journal article

Book Title

Entity type

Access Statement

Open Access

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