Fabrication and Characterization of E-Beam Deposited Copper Oxide Thin Film on FTO and Silicon Substrate for Optoelectronic Applications

In this work, an attempt has been made to fabricate a copper oxide thin film (TF) on both fluorine-doped tin oxide (FTO) glass substrate and a p-type Si substrate by simple E-beam evaporation techniques. To study the effect of annealing on the structure, morphology and optical properties of copper oxide-TF, the fabricated sample was annealed at 400 and 500 °C. The as-deposited copper oxide-TF/FTO sample shows the cuprous oxide (Cu2O) phase at ~ 42.84°, which corresponds to the crystal lattice plane (200) which is evidenced by the X-ray diffraction (XRD) analysis. Furthermore, annealing induced a phase transition in copper oxide-TF, resulting in two distinct peaks at ~ 34.98° and ~ 38.14°, which match the (11–1) and (200) CuO crystal planes. Again, optical properties of as-deposited copper oxide-TF/FTO indicate higher absorption in the near IR region. However, absorption intensity decreases in both the IR and visible range after annealing. Also, the optical bandgap of annealed copper oxide-TF/FTO decreases to ~ 2.26 eV which is determined from the Tauc Plot. Therefore, the proposed simple E-beam evaporation technique can be employed for the growth of good quality copper oxide film which may be used for various optoelectronic applications.