Probing structural, mechanical, electronic, optical, and transport properties of K2InSbX6 (X = Cl, Br) for optoelectronic and thermoelectric applications: DFT investigation

This article introduces and examines a new type of lead-free double perovskites, K2InSbX6 (X = Cl, Br) for their potential use in optoelectronic and thermoelectric devices. The investigation is conducted through theoretical exploration. The physical features of the materials were investigated using density functional theory. Both compounds are found stable in their cubic structure. Elastic constants and negative formation energies computed for K2InSbX6 demonstrate its mechanical and thermodynamic stability. According to the computed Poisson, Pugh's ratio, and anisotropy, both materials are brittle and show anisotropic behavior. Furthermore, the calculated findings show that K2InSbCl6 and K2InSbBr6 have direct bandgap values of 1.31 and 1.22 eV, respectively. Optical analysis reveals a notable ability to absorb visible and near-UV radiation. Perovskite K2InSbX6's excellent light absorption capabilities and narrow band gap make it a great choice for utilization in solar cell applications and other optoelectronic devices. Furthermore, the findings of transport characteristics indicate that the materials possess exceptional electrical and thermal conductivity and are projected to exhibit optimal thermoelectric capabilities at a temperature of 300 K.