First-principles study of electronic and optical properties of CdxMg1-xO alloys, TB-mBJ calculations

In this work, the structural, elastic, electronic, and optical properties of rock-salt CdxMg1 - xO were investigated using both exchange correlations the Local Density Approximation, and Wu-Cohen Generalized Gradient Approximation. The calculations were implemented using full-potential linearized augmented plane wave method in the framework of the DFT. For the electronic and optical properties, the calculations were performed using the Tran-Blaha modified Becke-Johnson. The lattice parameter has been reported for different cadmium concentrations x in the rocksalt structure. The calculated lattice parameter being transmitted quasi-linearly from 4.257 A to 4.43 A for rock-salt MgO and rock-salt CdO respectively. For rs MgO and rs CdO, the obtained results are very acceptable, with experimental results existing in the literature. The deviations between our results and experimental data is less than 1%. The estimated bandgap values are 7.39 eV for rs-MgO (rock salt) and 1.81 eV for rs-CdO; the results deviate by less than 5% from experimental results. The energy bandgap (Eg) for x = 0, 0.25, 0.50, 0.75, and x = 1 varied quasi-linearly. Moreover, the optical parameters of CdxMg1 - xO such as the dielectric function, the reflectivity, the refractive index, and the electron-loss-energy function, have also been studied and discussed. Our findings results for rs MgO and rs CdO are also in good agreement with the experimental data, our results prove that the plasma frequency varied non-lineary from 7.33 eV for rs-MgO to 3.03 eV for rs-CdO.