Modeling and Analysis of a Novel HTL-Free CsGeI3 Inorganic Perovskite Solar Cell Structure

The present study reports on the development of a novel HTL-free inorganic perovskite solar cell structure, which utilizes CsGeI3 as an active layer and TiO2 as an electron transport layer (ETL). One-dimensional solar cell capacitance simulator (SCAPS-ID) codes were used to model and analyze the HTL-free CsGeI3 PSC as a constructive technique. The photovoltaic performance parameters of the proposed PSC, such as open circuit voltage ($\mathrm{V}_{\mathrm{o}\mathrm{c}}$), short-circuit current density ($\mathrm{J}_{\mathrm{S}\mathrm{C}}$), fill factor (FF), power conversion efficiency, and quantum efficiency, are evaluated at different thicknesses, doping concentrations, and operating temperatures. The impact of back-contact on the HTL-free $\mathrm{C}\mathrm{s}\mathrm{G}\mathrm{e}\mathrm{I}_{3}$ cell has also been analyzed. The thicknesses of the ETL and the absorber have been optimized to be 25 nm and 1500 nm, respectively, for enhanced PV performance. As a result of the proposed HTL-free $\mathrm{C}\mathrm{s}\mathrm{G}\mathrm{e}\mathrm{I}_{3}$-based PSC, a power conversion efficiency of 14.27% was obtained along with a $\mathrm{V}_{\mathrm{o}\mathrm{c}}$ of 1.23 V, a Jsc of 16.45 $\mathrm{m}\mathrm{A}/\mathrm{c}\mathrm{m}^{2}$, and an FF of 78.22%. The simulation results have provided a framework for developing highly efficient and economically viable lead-free perovskites solar cells.