Prediction of optoelectronic properties for BexZnyCd1-x-ySe quaternary alloys :First-principles study

We present an Ab-initio investigation of optoelectronic properties of BexZnyCd1-x-ySe quaternary alloys. These properties have been calculated using the first-principles calculations based on the density functional theory. Generalized gradient approximation of Wu and Cohen (GGA-WC) has been used to compute the structural properties of BexZnyCd1-x-ySe for (x, y) = (0.125, 0.625), (0.250, 0.500), (0.375, 0.375), (0.500, 0.250) and (0.625, 0.125) and their end binaries as well as their ternaries. Results of structural parameters for end binaries (BeSe, ZnSe and CdSe) and (Be0.750Cd0.250Se and Zn0.750Cd0.250Se) ternaries agree with experimental values and theoretical data available in the literature. And, it has been found that the lattice constant of the BexZnyCd1-x-ySe decreases with increasing beryllium concentration. However, in order to calculate the electronic properties we employed the (LDA) and the recently (TB-m BJ) approaches. The band gap value increases with increasing Be concentrations. Furthermore, BexZnyCd1-x-ySe has a direct band gap. The optical properties, in terms of complex dielectric function, complex refractive indices, absorption coefficient, optical conductivity and normal-incidence reflectivity, of all materials under study have been calculated and discussed. Based on our obtained results, direct band gaps and optical parameters, BexZnyCd1-x-ySe quaternary alloys is very for manufacturing different microelectronic and, optoelectronic devices.