A First-Principles Study on ABBr3 (A = Cs, Rb, K, Na; B = Ge, Sn) Halide Perovskites for Photovoltaic Applications

Perovskite solar cells (PSCs) have received intensive attention and demonstrated power conversion efficiency (PCE) as high as 25.8%. Concerning Pb toxicity and the instability of organic elements, all inorganic lead-free perovskites (ILPs) have been extensively studied to achieve comparable or greater photovoltaic performance. To develop ILPs as an alternative for solar cell (SC) applications, first-principles calculations of ABBr perovskites (A = Cs, Rb, K, and Na, and B = Sn, and Ge) is performed. Structural, electronic, and optical properties are systematically studied to probe the potential for photovoltaic applications. These ILPs exhibit a direct bandgap in the range of 1.10-1.97 eV, which is highly beneficial for absorbing solar energy. Furthermore, these ILPs demonstrated significant optical absorption (over 10(5) cm(-1)) in the UV-Vis spectrum. These results will help design high-performance lead-free PSCs.

Automated summary

Inorganic lead-free perovskites show promising potential as alternatives for solar cell applications, with excellent photovoltaic performance and high solar energy absorption capabilities.