Theoretical Insights into Photovoltaic Application of a Novel Family of Perovskite‐Inspired Pb‐Free Metal Halide Materials

Organic–inorganic halide perovskite have shown great promise for photovoltaic applications due to their unprecedented optoelectronic properties and low manufacturing cost. However, the commercialization of this emerging technology is hampered by its thermal instability and intrinsic Pb‐toxicity. Here, we report first‐principles investigations on stability and optoelectronic properties of a series of all‐inorganic lead‐free metal halide perovskite‐like materials AMX 4 (A = Cs, Ag, and Rb; M = In, Sb, and Bi; X = Cl, Br, and I). Our calculations show that AgSbI 4 and AgBiI 4 have direct bandgaps of 1.63 and 1.44 eV, which possess strong interband optical absorption (≈10 5 cm −1 ). Based on these favorable properties, we also simulated the AgSbI 4 ‐ and AgBiI 4 ‐based thin film solar cells with the SCAPS‐1D code and achieve high PCE of 24.19% and 26.70%, respectively. These results reveal that the AMX 4 perovskite‐like materials could serve as potential alternatives to Pb‐based halide perovskites in photovoltaic devices.