DFT investigation of electronic, optical, mechanical and thermoelectric properties of ZnTe

Using full-potential linearized augmented plane wave (FP-LAPW) method, the structural, electronic, mechanical, optical and thermoelectric properties of ZnTe are studied in Zinc-blend structure at ambient conditions. All the calculations are carried out by using Density Functional Theory (DFT) implemented in Wien2k code, where the exchange-correlation functional is approximated using the Generalized Gradient Approximation (GGA). The DFT calculation produces better results for ground state properties lattice constant, volume, bulk modulus and total energy of ZnTe agreed well with available theoretical and experimental values. The ZnTe possess a direct band gap at the ‘Γ’ symmetry point with calculated energy gap value 1.03 eV revealing their semiconducting nature. The mechanical properties namely, Young’s modulus, Shear modulus, Poisson’s ratio and Hardness are also calculated. Based on the ductile/brittle analysis, ZnTe identified as ductile material suitable for flexible wearable thermoelectric applications. Using semiclassical Boltzmann transport theory, the thermo-efficiency of the material is analyzed based on the calculated thermoelectric properties namely Seebeck coefficient, electrical conductivity, power factor and figure of merit. The optical properties absorption, optical conductivity, eloss, dielectric constants, reflectivity and refractive index were calculated for the energy range between 0 - 13.98 eV.