Structural, Electronic, Thermoelectric and Optical Properties of Heavy Thallium Perovskite Tlpbx3 (X= Cl, Br, I) : A Computational Dft Study

By dint of FP-LAPW method employed in DFT technique, the mechanical stability, electronic behaviour, optical response and thermoelectric behaviour of Thallium based halide perovskites TlPbX 3 (X = Cl, Br, I) have been theoretically investigated. The energy volume optimisationcurves as well as formation energy and cohesive energy also confirms the structural stability of these perovskites. The electronic band structure plots as well as density of state plots of these compounds reveal their semiconducting nature using TB-mBJ-GGA and PBE-GGA approximation with wide band gaps for TlPbCl 3 and TlPbBr 3 . The optical constants such as the dielectric functions, refractive index, extinction coefficient, optical reflectivity, absorption coefficient, and transmittance are also calculated and discussed in detail. The chemical potential, carrier concentration as well as temperature dependence of Seebeck coefficient, electrical conductivity, electrical thermal conductivity, power factor, and figure of merit are investigated in detail using BoltzTrap code