Numerical study of eco-friendly Sn-based Perovskite solar cell with 25.48% efficiency using SCAPS-1D

Today's perovskite-based solar cells (PSCs) have become the fastest growing photovoltaic cells. The lead (Pb)-based PSCs attain the best efficiency, but despite their many advantages, these SCs have a major issue of its toxicity. The issue of toxicity is solved by using Pb-free perovskite material. Here, solar cell architecture comprising Pb-free perovskite, FTO/TiO2/CH3NH3SnI3/CZTS/Au is discussed. A fluorine-doped tin oxide (FTO) is used as a transparent conducting window layer and gold is used as a back contact. Titanium dioxide (TiO2) is used as an electron transport layer (ETL), while copper zinc tin sulfide (CZTS) is used as a hole transport layer (HTL). The PSC is simulated by using Solar Cell Capacitance Simulator (SCAPS-1D) software. The thickness of the absorber (CH3NH3SnI3) layer, ETL and HTL is varied. The operating temperature is also varied from 300 and 350 K. The best-chosen values of the acceptor density of absorber layer and HTL are 10(16) cm(-3) and 10(19) cm(-3), respectively, while the optimized donor density (N-D) of ETL is 10(20) cm(-3). The solar cell performance decreases with the increase in defect density (N-t). The performances of solar cell with and without HTL are also discussed, and maximum efficiency is achieved after the introduction of HTL. The designed Sn-based PSC exhibits the highest efficiency of 25.48% with an open-circuit voltage = 0.99 V, short-circuit current = 32.95 mA/cm(2) and fill factor = 77.77%.