First principle insights on mechanical, electronic and optical properties of direct bandgap material Cs2KScX6 (X=Cl, Br and I) for optoelectronic applications

Abstract

The development of materials with desired properties is essential for current technology. In this list, one more material is added for optoelectronic applications through the density functional theory calculations. This work covered the structural, mechanical, electronic and optical properties of Cs2KScX6 (X ​= ​Cl, Br, and I) double perovskite material. The designed double perovskites have a cubic crystal system with the space group of Fm-3m. The Cs2KScX6 (X ​= ​Cl, Br, I) double perovskites satisfies Born's mechanical stability criteria. The bandgap of the materials is in the range of 5.66 ​eV–3.56 ​eV, and the band edges are designated by Sc-3d orbital and p-orbitals of halide anions. The three perovskites have higher optical absorption in the UV regions, and the absorption is red-shifted concerning the ionic radius increment of halide anions. The results concluded that Cs2KScX6 (X ​= ​Cl, Br, I) is a possible material for UV region applications.