Impact of Photoluminescence Reabsorption in Metal-Halide Perovskite Solar Cells

Abstract

The precise quantification of the impact of photoluminescence reabsorption (PLr) in metal-halide perovskite solar cells (PSCs) has remained challenging. Here, the PLr effect is examined by combined time-resolved photoluminescence (TRPL) spectroscopy and time-resolved terahertz spectroscopy (TRTS) and a model is proposed which relates both the PLr and non-radiative recombination rate (k$_{nr}$) to the quasi-Fermi-level-splitting (QFLS). PLr is shown to be beneficial for the QFLS when k$_{nr}$ is below a critical value of ∽7×10$^5$ s$^{−1}$; at high k$_{nr}$ PLr is detrimental to the QFLS. By incorporating PLr into a two-diode model that allows extraction of the effective k$_{nr}$, the series resistance (r$_s$), and the shunt resistance (r$_{sh}$) in PSCs, we find that neglecting PLr overestimates the effective k$_{nr}$, while it does not affect the value of r$_s$ and r$_{sh}$. Our findings provide insight into the impact of the PLr effect on metal-halide PSCs.