This thesis consist of the analysis of electronic structures to diagnose the optical properties and thermoelectric characteristics of spinel compounds XZn2O4 (X = Ge, Sn)
having cubic structure. Properties are examined and required parameters are calculated with the help of DFT based FP-LAPW approach. The precise density of states (DOS) and
band structures (BS) diagrams, figured by using mBJ functional show the semiconducting natures of XZn2O4 (X = Ge, Sn) respectively. Also the direct band gaps of the studied compound reveals them optically active for the photonic applications and
optoelectronic devices. The total energies vs volume shows the structural stability for the studied compounds. Due to presence of strong hybridization among O atom with p-states, Zn with d-states, the Zn atom show decay in the magnetic moments also it occurs at the X site and O site. The plotted absorption coefficient approved for blue shift, hence the studied spinel oxides are recommended in optical applications. Also these spinel oxides are very suitable for thermoelectric devices and applications.