Computational screening of Cs based vacancy‐ordered double perovskites for solar cell and photocatalysis applications

Abstract The toxicity of lead ions in halide perovskite absorbing materials is the main bottleneck for practical application. To replace the traditional lead halide perovskites by environmental friendly double perovskite, computational tools based on density functional theory were employed to predict the intrinsic properties of potential double perovskites to efficiently and rapidly find more double perovskites with properties suitable for optoelectronic applications. Screening homovalent alternatives for B and X‐site ions in vacancy‐ordered double perovskite Cs 2 BX 6 for solar cell applications and photocatalyst was done using Perdew–Burke–Ernzerhof and Heyd–Scuseria–Ernzerhof functional with spin‐orbit coupling. Three empirical factors and formation enthalpy were used to evaluate the stability of 30 materials at different temperatures. Finally, the Cs‐based vacancy‐ordered double perovskites with suitable bandgap for optoelectronic applications can thus be obtained. Using computational techniques, this study can also provide theoretical guidance for the rational design of possible double perovskite materials with improved photocatalytic characteristics. image