Abstract:
Highly photoactive Cl-doped Cu2O films were electrodepos ited potentiostatically on Ti substrates. Optimum deposition
potential was determined by Linear-Sweep Voltammetry
measurements. The influence of chlorine doping on grain
size, crystallite shape and orientation was examined using
scanning electron microscopy and X-ray diffraction. X-ray
photoelectron spectroscopy confirmed the presence of Cl due
to doping. Mott–Schottky electrochemical impedance analysis
showed the p-type conductivity for undoped Cu2O films and n type conductivity for Cl-doped Cu2O films. Analysis also
showed that the carrier concentration of Cu2O thin films varied
with Cl concentration of the deposition bath. Spectral
responses of the resulting films were investigated in a
photo-electrochemical cell to optimize the CuCl2 concen tration of the deposition bath to obtain highly photoactive
films. Photocurrent measurements further confirmed that the
conductivity of these Cl-doped Cu2O films was n-type while
undoped films showed p-type conductivity at a bath pH 9.3.
The resistivity of Cu2O films decreased with the Cl
concentration and the resistivity obtained for the Cl-doped
Cu2O films with the highest photoactivity was about 102 Vcm
at 30 8C. The low resistance and high photoactivity of Cl doped cuprous oxide thin films make them more suitable for
solar cell and other applications.
