Evaluation of Physical Properties of A₂ScCuCl₆ (A = K, Rb, and Cs) Double Perovskites via DFT Framework

Herein, the structural, mechanical, optoelectronic, and transport properties of double perovskites A₂ScCuCl₆ (A = K, Rb, and Cs) have been determined through simulations using density functional theory. The stability of K₂ScCuCl₆, Rb₂ScCuCl_6, and Cs₂ScCuCl₆ compounds is supported by the optimization of structural configuration and estimation of negative formation energy. The mechanical parameters are computed to quantify mechanical strength, stability, and anisotropy. The compounds that were investigated exhibit semiconductor properties, with an indirect bandgap of 1.55, 1.43, and 1.30 eV using TB-mBJ potential, respectively. The density of states also reveals the band gap and semiconductor properties of the materials. The optical characteristics of the materials have been analyzed in terms of the dielectric function, absorption, reflectance, and optical loss. The projected low excitons binding energy, high absorbance in visible and ultraviolet regions, minimal reflectivity, and energy loss suggest that these materials are highly recommended for utilization in solar energy technology. We examined the transport characteristics that vary with temperature. The combination of high electrical conductivity, moderate thermal conductivity, and higher ZT values of 0.81, 0.86, and 0.77 makes them promising candidates for thermoelectric applications. This analysis ensures that these materials can be utilized in energy conversion applications.