Current transport mechanisms of n-ZnO/p-CuO heterojunctions

In this study, n-ZnO/p-CuO heterojunction have been fabricated by sol-gel dip-coating technique which is simple and inexpensive. The structure of the p-CuO/n-ZnO was analyzed by X-ray diffraction spectroscopy and UV-VIS spectroscopy. The electrical junction properties were characterised by temperature dependent current-voltage (I-V) characteristics and at high frequency capacitance-voltage (C-V) characteristic at room temperature. The structure showed non-ideal behaviour of I-V characteristics with an ideality factor of 3.5 at room temperature. Temperature dependent forward current-voltage measurements suggest that trap-assisted multi-step tunnelling is the dominant current mechanism in this structure.