Unveiling the potential of lead-free KInBr <sub>3</sub> and RbInBr <sub>3</sub> perovskites: a breakthrough in optoelectronic and photovoltaic performance through DFT (HSE hybrid functional) and SCAPS-1D simulations
Sudipta Dash, Debidatta Behera, Sangram Kishore Mohanty, G. Palai, Ipsita Mohanty
Abstract
Lead-free halide perovskites are emerging as promising materials for solar cells due to their exceptional properties. KInBr₃ and RbInBr₃ are particularly notable, showing great potential for lead-free perovskite solar cells (PSCs). Using density functional theory (DFT) with the VASP framework, we investigated their structural, electronic, and optical properties. Both materials exhibit direct band gaps, with 0.93 eV for KInBr₃ and 0.77 eV for RbInBr₃, calculated using the hybrid HSE functional. The density of states (DOS) analysis reveals that the In s/p orbitals dominate the band edges, making these materials suitable for photovoltaic applications. Optical studies confirm strong light absorption in the visible and ultraviolet regions. Furthermore, SCAPS-1D simulations for a solar cell with the structure Ag/MoO₃/KInBr₃/ZnO/ITO yielded a power conversion efficiency (PCE) of 30.25%, demonstrating the exceptional potential of KInBr₃ for high-performance solar energy technologies.