Tuning the Optoelectronic Properties of Rock Salt Ba2XSbO6 (X = In, Sc) Double Perovskite Oxides via B-Site Cation Substitution

In the present study, we examine the effects of B-site cation substitution on the optoelectronic characteristics of $\text{Ba}_{2}\text{XSbO}_6$ (X = In, Sc) using the WIEN2k code. The results verified the cubic structure of both materials with a space group of Fm-3m and lattice constants of 8.2787 Å and 8.1904 Å for $\text{Ba}_{2}\text{InSbO}_{6}$ and $\text{Ba}_{2}\text{ScSbO}_{6}$ respectively. Moreover, the present work emphasizes the possibility of B-site cation substitution to improve the electrical and optical behavior of the studied materials, so lowering the band gap from 4.023 eV for $\text{Ba}_{2}\text{ScSbO}_{8}$ to 1.419 eV for $\text{Ba}_{2}\text{InSbO}_{6}$. Such changes show the great influence of B-site engineering on the electronic characteristics of a material since they increase light absorption, optimize electronic transport, and strengthen material stability.