Optoelectronic characteristics of In₂O₃/CuO thin films for enhanced vis-light photodetector

In₂O₃ and In₂O₃/CuO multilayer films were prepared using dc reactive magnetron sputtering for the possible usage as Vis-light photodetector. The structural, morphological, optical, and I–V characteristics were examined. X-ray diffraction revealed the presence of polycrystalline cubic In₂O₃ and monoclinic CuO phases. The EDAX elemental mapping of In₂O₃/CuO multilayer inferred the existence of well-distributed In, Cu, and O elements. Semi-rounded and uniformly distributed nano-grains were observed for In₂O₃ thin films, whereas nano-grains elongated from bottom to top with more open structure were observed in In₂O₃/CuO multilayers thin films. Analysis of the optical properties revealed that In₂O₃/CuO multilayer films have higher absorption, higher refractive index, and lower optical band gap of 1.82 eV which inferred that CuO film controls the optical properties of In₂O₃/CuO multilayer thin films. The In₂O₃/CuO multilayer thin films showed linear relationship phenomenon between voltage and current in both forward and reverse bias conditions. A higher magnitude of current is obtained in the circuit under Vis-light illumination.