Computational study of novel scandium and lithium perovskites based materials for sustainable energy devices
摘要
The current first-principles density functional theory (DFT) study explores how anionic affects substitution structural, electronic, thermodynamic, mechanical, and optical features of lead-free halide-based double perovskite K2ScLiX6 (X = F, Cl). Both materials are crystallized in a stable cubic structure that has lattice constants of 8.29 Å (X = F) (and 10.13 Å (X = Cl), both confirmed by tolerance factors of 0.97 and 0.93 and negative formation energies. Direct band gaps of 6.34 eV and 3.78 eV are reported as calculated by the electronic structure of K2ScLiF6 and K2ScLiCl6, respectively. Mechanically, fluoride material is stiffer and ductile (B = 41.41 GPa, E = 57.77 GPa, B/G = 1.82), while the chloride is softer and brittle (B = 21.28 GPa, E = 33.32 GPa, B/G = 1.58). Thermally, K2ScLiF6 displays superior stability (