Influence of Zinc Doping on the Morphological, Structural, and Optical Characteristics of Copper Oxide Thin Films Prepared Through Ultrasound Spray Pyrolysis

O thin films was estimated from the transmittance data by applying the Tauc plot method. A decrease in the band gap was observed at higher doping concentrations. It can be confirmed that no secondary phases are observed at a doping level of 20.0 at. % of zinc, indicating good solubility of zinc in CuO. The analysis and discussion of these findings are included throughout this work to elucidate the controversies noted in the literature.