INSIGHT INTO STRUCTURAL, OPTICAL AND ELECTRICAL PROPERTIES OF COBALT OXIDE Co3O4 THIN FILM

In the present paper, experimental investigations on structural, morphological, optical and electrical properties of Co3O4 thin film deposited by spray pyrolysis method are reported. Using the interplanar spacing of the XRD reflection and Scherrer formula, respectively, we observed that the obtained films identified crystallize in the cubic spinel structure with a=0.8245 nm and d=19 nm. From the SEM picture, a dense grain in the morphology of Co3O4 is detected which has a uniform spherical shape. In addition, transmittance, absorbance, optical bandgap and extinction coefficient of the film versus incident photon energy were calculated. We found that Co3O4 film has a direct bandgap and direct forbidden transition varying from 1.69 eV to 2.85 eV and 1.62 eV to 1.88 eV, respectively. Further, the variation of (DC) electrical resistivity with temperature (from the room temperature of 27 degrees C to 350 degrees C) shows that the electrical resistivity was decreased with increasing temperature indicating a semiconducting transport behavior.