Structural, electrical, and photoelectric properties of p-NiO/n-CdTe heterojunctions

p-NiO/n-CdTe-photosensitive heterojunctions were prepared by the deposition of nickel oxide thin films onto n-type single-crystal CdTe substrates by DC reactive magnetron sputtering. The analysis of capacitance-voltage (C-V) characteristics, measured at different frequencies of the small amplitude AC signal and corrected by the effect of the series resistance, provided evidence of the presence of electrically charged interface states, which significantly affect the measured capacitance. The dominant current transport mechanisms in the heterojunctions were determined at forward and reverse biases. Using "light" I-V characteristics, we determined the open-circuit voltage V_oc=0.42 V, the short-circuit current I_sc=57.5 μA/cm², and the fill factor FF=0.24 under white light illumination with the intensity of 80 mW/cm².