Photovoltaic properties of halide perovskites for solar cell application with efficiency greater than 18

The opto-electronic properties and solar cell efficiency of halide perovskites A₂LiInBr₆ (A = Rb, Cs) are investigated using density functional theory (DFT) through WEIN2k and SCAPS-1D. The electronic characteristic of A₂LiInBr₆ (A = Rb, Cs) compounds reveal their direct bandgap semiconductor nature and are active in visible rang. The results indicate that substituting Cs with Rb causes a slight narrowing of the bandgap. According to the optical analysis, these compounds possess dynamic visible-range optical properties that make them ideal for application in opto-electronic devices and solar cells. The A₂LiInBr₆ (A = Rb, Cs) absorber layer is employed to simulate the solar cell efficiency of these lead free perovskite-based device. The optimized FTO/WS₂/A₂LiInBr₆ (A = Rb, Cs)/Spiro-MeOTAD/Cu solar cells exhibit the best performance with WS₂ as the ETL and Spiro-MeOTAD as the HTL having V _oc value of 2.27 V and 1.85 V, J _sc value is 11.35 and 11.44 mA cm^-2, FF is 73.24% and 83.84%, PCE is 18.88% and 17.97%, R _s is 9.94 and 4.88 Ω cm² and R _sh is 1.35 and 1.14 Ω cm² respectively. As a result, this research paves the way for future experiments to create entirely inorganic perovskite photovoltaics, free of lead toxicity and exhibit improved photovoltaic ability.