Structural and optoelectronic properties of rock salt magnesium cadmium oxygen ternary alloys: For ultraviolet applications

In this work, we present a comprehensive investigation regarding the physical properties of MgxCd1-xO ternary alloys for different concentrations (0≤x≤1), in rock salt phase. These properties, including structural, electronic, and optical properties, were studied using the full-potential linearized augmented plane wave (FP-LAPW) method based on the density functional theory (DFT) with the Wien2k code. The structural parameters of RS MgxCd1-xO are studied in detail as a function of Mg concentration using the generalized gradient approximation (GGA–PBEsol). The calculated structural parameters of both binaries are in good agreement with their corresponding theoretical and experimental data. The results show that the value of the lattice parameter of RS MgxCd1-xO decreases almost linearly with the increasing Mg concentration and exhibits a small deviation from the linear composition dependence (LCD). Both approximations (LDA) and (TB-mBJ) were used to explore the electronic properties. It is found that the increasing Mg concentration leads to increasing energy band gap. Our obtained results demonstrate that the RS CdO has an indirect band gaps and RS MgO has a direct band gap, while RS MgxCd1-xO ternaries (0.125 ≤ x ≤ 0.875) exhibit an indirect band gap semiconductors. Additionally, the linear optical properties including, complex dielectric function, complex refractive index, absorption coefficient, optical conductivity and absorption coefficient, are calculated and discussed in detail. Our obtained results are discussed in detail and compared with existing data in the literature. These results confirm that the RS MgxCd1-xO ternary alloys are a promising candidate for ultraviolet photo electronic devices.