Impact of Photoluminescence Reabsorption in Metal‐Halide Perovskite Solar Cells

by Mingcong Wang, Kai Wang, Yajun Gao, Jafar I.Khan, Wenchao Yang, Stefaan De Wolf, Frédéric Laquai

Research Article Year: 2021 DOI: https://doi.org/10.1002/solr.202100029

Bibliography

Wang, M., Wang, K., Gao, Y., Khan, J.I., Yang, W., De Wolf, S., Laquai, F. Solar RRL (2021)

Extra Information

An analytical solution of photoluminescence reabsorption (PLr) is used to determine the intrinsic radiative carrier recombination rate of metal-halide perovskite films. Simulation of its impact on the quasi-Fermi-level splitting (QFSL) reveals it is detrimental at high but advantageous at low nonradiative recombination rates. Importantly, neglecting PLr results in overestimation of the effective nonradiative recombination rate in perovskite solar cells.

Abstract

The precise quantification of the impact of photoluminescence reabsorption (PLr) in metal‐halide perovskite solar cells (PSCs) remains challenging. Herein, the PLr effect is examined by combined time‐resolved photoluminescence (TRPL) spectroscopy and time‐resolved terahertz spectroscopy (TRTS) and a model is proposed that relates both, the PLr and nonradiative recombination rate (knr) to the quasi‐Fermi‐level splitting (QFLS). PLr is shown to be beneficial for QFLS when the nonradiative recombination rate (knr) is below a critical value of ≈7 × 105 s−1; at high knr PLr is detrimental to QFLS. By incorporating PLr into a two‐diode model that allows extraction of the effective knr, the series resistance (rs), and the shunt resistance (rsh) in PSCs, it is found that neglecting PLr overestimates the effective knr, although it does not affect the value of rs and rsh. The findings herein provide insight into the impact of the PLr effect on metal‐halide PSCs.

Keywords

nonradiative recombination passivation strategies perovskite solar cells photon recycling quantum efficiency transient spectroscopy