Computational Design of Perovskite BaxSr1–xSnO3 Alloys as Transparent Conductors and Photocatalysts

Abstract

Using a first-principles-based multiscale computational approach involving density functional theory and the cluster expansion method, we produced the structural evolution for the perovskite BaxSr1–xSnO3 system in relation to its Ba:Sr composition from the formation energies of different alloy configurations and demonstrated their use as tunable alloy transparent conductors and photocatalysts via structural, electronic, and optical studies. The predicted phase diagram revealed the transformation of the structure of BaxSr1–xSnO3 from orthorhombic to tetragonal and finally to cubic with increasing x, forming disordered solid solutions for 0 < x < 1 that is entropically stabilized against phase segregation. This trend is similarly observed in the published experiments. A special quasirandom structure approach is used to model the disordered solid solutions of the BaxSr1–xSnO3 alloys. Structural analyses have indicated that the decrease in Ba:Sr ratio is associated with the decrease in unit cell volume, and a...