Influence of substrate temperature on the characteristics of CO3O4 thin layers

This study explores the fabrication of cobalt oxide films using the spray pyrolysis process. In this procedure, an aqueous cobalt chloride solution is sprayed upon a pre-heated glass substrates at temperatures between 250°C and 400°C. Various techniques, which includes X-ray, scanning electron microscopic (SEM), four-point probe method, and the optical absorption spectrometric are employed to assess and analyze the structural, morphological, optical, and electrical characteristics of the fabricated layers. XRD results emphasized the controlled formation of Co₃O₄ with a cubic crystalline structure. Surface morphology analysis revealed the presence of cobalt oxide clusters and nanocrystalline grains. Optical measurements indicated a direct bandgap value between 1.46 and 2.05 eV, while the highest observed conductivity, recorded at a substrate temperature of 400°C is 1.29 S/cm.