Electrical characterization of DC sputtered ZnO/p-Si heterojunction

ZnO thin films were formed on a p-Si semiconductor and a glass by DC sputtering technique. The ZnO films were analyzed using UV–vis spectroscopy and X-ray diffraction (XRD). Electrical and photoelectrical parameters of ZnO/p-Si heterojunction were determined by current–voltage (I–V), capacitance–voltage (C–V) and capacitance–frequency (C–f) of the device in dark and under the light with 100 mW/cm2 and AM 1.5 illumination property. The device had a good rectifying property with 1.35 ideality factor, 0.76 eV barrier height and 6.69 kΩ series resistance values. It was seen that I–V, C–V and C–f measurements of the heterojunction had good sensitivity to the light and the device behaves as a photodiode and a photocapacitor.

► DC sputtered ZnO thin films were grown on a p-Si wafer and a glass and their orientation (0 0 2) and optical band gap (3.28 eV) were determined.
► Electrical parameters of ZnO/p-Si heterojunction such as ideality factor, barrier height and series resistance were calculated as 1.35, 0.76 eV and 6.69 kΩ⋅
► The effects of light on current–voltage, capacitance–voltage and capacitance–frequency properties of the ZnO/p-Si heterojunction were examined under 100 mW/cm2 and AM 1.5 illumination conditions.