A First‐Principles Study on ABBr<sub>3</sub> (A = Cs, Rb, K, Na; B = Ge, Sn) Halide Perovskites for Photovoltaic Applications
Dibyajyoti Saikia, Mahfooz Alam, Jayanta Bera, Atanu Betal, Appala Naidu Gandi, Satyajit Sahu
Abstract
Abstract 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 3 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.