Abstract
Ab-initio computations are performed to analyze the Lead-free double perovskites Cs2AgZBr6 (Z = Bi, Sb)for solar cells and renewable energy. Modified Becke and Johnson potential (TB-mBJ) has been adopted to compute the electronic and optical properties. The computed lattice constants are found in good agreement with the reported experimental data. Band gaps calculations for Cs2AgBiBr6 and Cs2AgSbBr6 reveal their indirect nature and are quantified 2.0 eV and 1.39 eV which make them potential candidates for visible light solar cells. The optical spectra have been elaborated in terms of dielectric constants, absorption of light, refractive index, and reflection of light. The maximum absorption bands are recorded in the wavelength range of 620 nm-310 nm. Finally, thermoelectric properties are calculated by BoltzTraP code, which depicts high values of Seebeck coefficient and low thermal conductivity. Thus, performed theoretical calculations suggest the studied materials for potential application in renewable energy field.