Effect of Creating Oxygen Deficiency on the Optical Characteristics of CdO: A DFT based theoretical study

Abstract

This study presents detailed computational research using density functional theory (DFT) with the PBE-GGA functional and Material Studio software to investigate the optical characteristics of pure CdO and oxygen-deficient CdO at the supercellular level. The study optimizes the structures of both CdO configurations with convergence tests which are confirmed result with structural deviations of 4.1% for simple CdO and 4.2% for oxygen-deficient CdO, respectively. The optical characteristics are afterwards examined, including the conductivity, loss function, dielectric function, and refractive index. The dielectric function for both structures exhibits distinct features, with significant absorption peaks in the region of 2.9-10 eV for oxygen-deficient CdO and a band gap at 2.58 eV for simple CdO, according to the research. The refractive index remains constant at lower energies while the conductivity curves show excitonic behavior on inducing oxygen deficiency at the supercellular level. In addition to this, the loss function exhibits peaks indicating various excitations and absorption activities. It is worth mentioning here that understanding these properties contributes to the development of optical devices, and the computational approach offers a powerful tool for atomic-level investigations.