Fabrication and characterization of oxide heterojunctions prepared by electrodepositing cuprous oxide on conductive glasses

The properties of oxide heterojunctions prepared by electrodepositing Cu₂O on commercial F-doped SnO₂ (FTO) and Sn-doped In ₂O₃ (ITO) glasses were studied. The X-ray diffraction patterns showed that Cu₂O films grown on both FTO and ITO glasses are mainly (111)-oriented. The optical band gap of the electrodeposited Cu ₂O films grown on FTO glass determined from the absorption spectrum is about 2eV. A peak with a wavelength of 622nm that could be correlated to the near band edge emission was observed in the photoluminescence spectrum. Nonlinear and rectifying behaviors were observed in the current-voltage measurements of these fabricated heterojunctions. Furthermore, the high turn-on voltage of 4.7 V indicates the absence of defect states at the interface of the Cu₂O/FTO heterojunction. Moreover, thermal annealing on Cu ₂O/FTO heterojunctions may cause Cu diffusion into the n-type layers.