Comprehensive Investigation of Relative Permittivity Effects on Perovskite Solar Cell Performance Using SCAPS-1D and Impedance Spectroscopy

Perovskite solar cells (PSCs) are promising photovoltaic technologies, yet their performance is critically influenced by the relative permittivity (εr) of the active layer, which governs charge carrier dynamics. This study employs SCAPS-1D simulations coupled with complex impedance and modulus spectroscopy to systematically investigate the impact of varying the εr of the MAPbI3 layer from 4 to 12. We find that while the open-circuit voltage (Voc~1.05 V) and short-circuit current density (Jsc~25 mA cm−2) remain stable, the FF and efficiency η (%) decline from 78% to 70% and 20% to 17%, respectively, with increasing εr. Impedance analysis deconvoluted this trend, revealing a decrease in recombination time (τ1) and a peak in ionic transport time (τ2) at εr = 7. The optimal performance of 18.86% was achieved at a lower εr, demonstrating that minimizing recombination losses through permittivity engineering is crucial for advancing PSC efficiency.