Advancements in device modelling and impedance analysis of a high performance disilicide (FeSi2)-based perovskite solar cell

In the recent years, there have been remarkable concerted efforts to design and fabricate solar cell architectures of high solar harvesting capabilities. Behind this operation is to understand material combinations and device physics that would deliver a high performance solar cell. Although previously we reported the electrical performance metrics such as power conversion efficiency of the solar cell architecture, ITO/TiO2/FeSi2/CuSCN/Ni, herein, we analyze extensively the performance of the model cell, focusing mainly on band gap, carrier lifetime analysis, and impedance spectroscopy with a wide frequency range of 10−3 Hz–1012 Hz to study diffusion processes and evaluate device performance. Further, series (Rs) and shunt (Rsh) resistances is also examined to determine their impact on the performance metrics of the model cell structure. Analysis of alternating current (AC) characteristics revealed complex impedance (Z∗) and modulus (M∗) indicative of ionic transport, recombination, and diffusion processes crucial for optimization. An appropriate equivalent circuit model was developed and validated through deconvolution and theoretical considerations, yielding parameters such as the time constant for each process. It was observed that ionic conductivity and electronic diffusion play key roles in balancing charge collection and recombination dynamics necessary in understanding interface quality of the solar cell device.