Fabrication and electrical characterization of p-Cu ₂O/n-ZnO heterojunction

The conducting metal oxide (ZnO, Cu ₂O) films were used for fabrication of p-n heterojunction by rf sputtering and electrodeposition techniques respectively. The as synthesized films were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), UV spectroscopy and electrical techniques. The electrical properties of the p-Cu ₂O/n-ZnO heterojunction were examined using the current-voltage measurements. The current-voltage (I-V) result showed that potential barrier was higher than the turn-on voltage, which was attributed to the presence of the interface defect states. The PN junction parameters such as ideality factor, barrier height, and series resistance were determined using conventional forward bias current-voltage characteristics. The annealing of Cu ₂O increase the crystallinity size and which enhance the photo current from 1.6 mA/cm ₂ to 3.7 mA/cm ₂. The annealing of respective film resulted in a decrease of these parameters with an increase in efficiency of solar cell from 0.14% to 0.3% at 350 °C.