Computational insight into the structural, electronic, mechanical, optical and thermoelectric properties of ZnSe - DFT Study

Flexible thermoelectric materials are receiving more attention than bulk thermoelectric materials due to their capacity of converting heat into electricity directly along with easily contact with curved heat sources.  The present study mainly focused on the structural, elastic, mechanical, optical and thermoelectric properties of Zinc-based binary chalcogenide ZnSe belongs to II-VI semiconductors by means of Density Functional Theory (DFT) using Wien2k software.   The DFT calculation produces better results for electronic and transport properties of II - VI semiconductors.  The obtained ground state properties lattice constant, volume, bulk modulus and total energy of ZnSe agreed well with existing theoretical and experimental values. The zinc blend cubic ZnSe possess a direct band gap at the Γ with calculated energy gap value 1.061 eV revealing their semiconducting nature. The thermoelectric properties namely Seebeck coefficient, electrical conductivity, lattice thermal conductivity, power factor and figure of merit have been calculated for ZnSe using semiclassical Boltzmann transport theory.  The optical properties absorption, optical conductivity, eloss, dielectric constants, reflectivity and refractive index were calculated for the energy range between 0 - 13.7 eV. Based on the ductile/brittle analysis, ZnSe identified as ductile material suitable for flexible wearable thermoelectric applications.