Impact of Photoluminescence Reabsorption in Metal‐Halide Perovskite Solar Cells.

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. [ABSTRACT FROM AUTHOR]