A DFT approach to explore the structural, mechanical, and optoelectronic of indium-based InXY3 (X = Ca, Sr, Ba; Y = Cl, Br) halide perovskites for photoelectric applications

This study employs density-functional theory to investigate the structural, mechanical, and photoelectric properties of indium-based halide perovskites InXY3 (X = Ca, Sr, Ba; Y = Cl, Br) for the first time. The PBE functional is used for calculation the structural and mechanical properties. Cubic InXY3 crystals are determined to possess mechanical and thermodynamic stabilities, as indicated by the calculated elastic constants and formation energy. Based on the B/G ratio, Poisson's ratio, they are ductile and ionic compounds. The HSE06 functional is employed to calculate the optoelectronic properties with accuracy. Their band structures indicate that InXCl3 are direct (X- X) wide bandgap semiconductors, while InXBr3 are indirect (X-R) wide bandgap semiconductors. The optical properties show that all materials demonstrate significant transmission in the visible and infrared regions and strong absorption in the UV region. Thus, they are suitable as transparent materials for infrared and visible light and candidate materials for UV absorbers.