Influence of chalcogenides on the optoelectrical properties of semiconductor ternary alloys Zn₀.₉₅Cd₀.₀₅X (X=S, Se and Te): A DFT study

Abstract

In this article comprehensive study of the thermoelectric and optical properties of the Zn₀.₉₅Cd₀.₀₅X (X = S, Se and Te) by using first principle DFT calculation incorporating the Wien2k code, has been considered. Firstly, we determined the optimized structural parameters, comprising of the atomic coordinates. All the properties like the energy band structure, densities of electronic states and energy dependence of the optical functions were figured out. We found the decrease in their band gaps (3.5 eV, 3.0 eV and 1.9 eV respectively) as we replace S by Se and Te, respectively. We found that they are having direct band gap having transition along Γ- Γ symmetry point. The electronic interband transitions accountable in the optical spectra were specified. In parallel the standard Boltzmann transport theory were used to calculate the thermoelectric parameters, including Seebeck coefficient, electrical and thermal conductivities and figure of merit. In response we found that the investigated compounds are potential candidates for thermoelectric applications.