Mixed Compounds of Cd1-xMgxO (0≤x≤1) and Their Optoelectronic Properties

The engineering of bandgap in materials is desired to develop new optoelectronic and photonic devices. The structure, electronic and optical properties of MgO (an insulator) mixed with CdO (a semiconductor) in the stoichiometry (0) are calculated using the ab initio density functional theory. The bond character changes from partial covalent to a more stronger covalent bond as Cd concentration increases in MgO. The dominant covalent bond, coupled with high bulk modulus values predicts that the mixed compounds are hard materials and that Cd and Mg compliments each other to increase the hardness. All the mixed compounds are indirect bandgap materials. The dielectric function and the refractive index shifts to lower energy domain as Cd concentration increases, indicating that the optoelectronic property of the compounds is Cd dependent. The evaluated optoelectronic property predicts the material to be effective for applications in the visible and UV regions of the energy spectrum.