Computational study on elastic, electronic, optical and thermodynamic properties of Ba2BiInO6 perovskite compound

We present a first-principles investigation of the electronic, elastic, optical and thermodynamic properties of the double perovskite compound Ba 2 BiInO 6 using density functional theory (DFT) with the PBE and PBEsol exchange–correlation functionals. Our calculations were centered on two distinct cubic phases: a Fm 3 ¯ m phase with a 0.0 eV bandgap and a Pn 3 ¯ 1 phase with a small bandgap of 0.2087 eV. Our computed lattice constants align well with existing theoretical data indicating the validity of the study. The calculated elastic constants of Ba 2 BiInO 6 satisfy the Born mechanical stability criteria for cubic crystals suggesting that both phases are mechanically stable. Significantly, Pn 3 ¯ 1 phase of Ba 2 BiInO 6 is predicted to absorb light in the ultraviolet–visible (UV–Vis) spectrum. Our finding suggests that Ba 2 BiInO 6 in Pn 3 ¯ 1 phase is a promising material for application in the development of buffer solar cells and other optoelectronic devices, particularly in low band-gap applications, potentially enhancing their efficiency. • Fm 3 ¯ m phase has zero band-gap while Pn 3 ¯ 1 has a 0.2087 eV gap between the conduction and the valence band. • Pn 3 ¯ 1 phase has good optical absorption over a range of EM spectrum while Fm 3 ¯ m has greater EM reflectivity • Both phases are mechanically and thermodynamically stable.