Enhanced thermoelectric and optical response of Ag substituted Cu2O compositions for advanced applications

Abstract

Cu2O based semiconductor materials are promising candidates for modern electronic devices due to have excellent electronic and optical properties. In this work, pure and Ag doped Cu2O structures were simulated using density functional theory in the framework of wien2k code with generalized-gradient-approximation under full potential linearized augmented plane wave approach. Experimentally, pure and Ag doped Cu2O uniform thin films were successfully fabricated. The morphology and elemental compositions of thin films were investigated using field emission scanning electron microscopy and energy dispersive x-rays spectroscopy, respectively. X-ray diffraction analysis exhibited cubic phase having space-group 224-Pn-3m in all synthesized thin films. Total density of states spectra for Ag containing compositions present overlapping of states at Fermi level. Thermoelectric properties show a significant variation in various parameters with the change in temperature and Ag content in structure. The see-beck coefficient was observed to vary from 0.0002 to 0.00035 Vk−1 for pure and Ag doped Cu2O compositions. The optical parameters like extinction and absorption curves attains maximum values at higher photon energies. The refractive index presents an enhanced transmittance power with the increment in photon energy. The band gap was found to reduce from 2.33 eV to 1.99 eV with Ag doping attributed to the sharp increase in optical conductivity.