Systematic Study of Optoelectronic and Thermoelectric Properties of New Halide Double Perovskites Cs2TlBiX6 (X=Cl, Br and I) for Energy Harvesting Applications

In this study we preferred to substitute hybrid halide perovskites (CH 3 NH 3 PbI 3 ) by using First principles calculations based on WEIN2K. To achieve renewable energy applications, the expansively investigate structured, optoelectronic, elastic, and thermoelectric characteristics of Cs 2 TlBiX 6 (X= Cl, Br, and I) double perovskite. The elastic properties in these investigations display ductile behavior. Direct band gaps (2.29 eV, 2.26 eV, and 1.63 eV) exhibited by Cs 2 TlBiX 6 (X=Cl, Br and I) respectively. We have examined dielectric constants, refractive index, absorption coefficient, optical conductivity in optical properties. All compounds have high UV absorption coefficients, indicating that they are suitable for solar cells and other optical devices. In the temperature range of 200-800K, the thermoelectric and thermodynamic properties were calculated.