Current flow mechanism in Cu2O/p-Si heterojunction prepared by chemical method

Cu2O thin films were chemically deposited on single-crystal p-Si substrates to form Cu2O/p-Si heterojunctions. The structure of the Cu2O films was analysed by x-ray diffraction spectroscopy and UV-Vis-NIR transmittance spectra. In order to investigate the dark current transport mechanism in Cu2O/p-Si heterojunctions the current-voltage characteristics were measured in the temperature range 120-320 K and capacitance-voltage characteristics at a high frequency of ~1 MHz at room temperature. The I-V-T characteristics revealed that the forward current was determined by trap-assisted multi-step tunnelling. The activation energy determined from the saturation current and the junction built-in potential determined from the capacitance-voltage characteristics were about 0.18 eV and 1.10 V at room temperature, respectively.