Optimizing the Efficiency of Lead-Free Cs2TiI6-Based Double Halide Perovskite Solar Cells Using SCAPS-1D

Conventional lead halides perovskites have attracted much attention to become a next-generation solar technology. Besides their low cost and excellent efficiency, high toxic nature and device instability become the major issue to limit their wide applications. Ti-based (Cs2TiI6) double halide perovskite solar cells (PSCs) have emerged as a potential candidate to become the best alternate. However, poor device efficiency is still a restriction. Therefore, proper optimization and deep device analysis are needed to explore the full potential of Cs2TiI6-based PSCs. In the present research work, the open-circuit voltage (V-oc), current density (J(sc)), fill factor (FF), and power conversion efficiency of Cs2TiI6-based PSC are successfully optimized. The device optimization is performed using the different combinations of electron transport layers and hole transport layers along with absorber thickness, acceptor doping density, and interface defect density. The effect of R-series and R-shunt is explored and identified the best device efficiency of 28.07% along with other photovoltaic (PV) parameters; V-oc = 1.41 V, J(sc) = 22.44 mA cm(-2), and FF = 88.15%, respectively. The supportive analysis of C-V and Mott-Schottky characteristics helps to get deep insight into the device's performance. Furthermore, the resultant PV parameters are compared to the previous studies as well.