Electrical and ultraviolet photoresponse properties of quasialigned ZnO nanowires/p-Si heterojunction

The authors report on the electrical and ultraviolet (UV) photoresponse properties of quasialigned ZnO nanowires (NWs)/p-Si heterojunction grown by a low-temperature solvothermal technique. The current-voltage characteristic of a single ZnO NW/p-Si junction measured by a scanning tunneling microscope shows a rectifying behavior with a rectification ratio I-F/I-R of 33 at 5 V. The current transport is dominated by the recombination-tunneling mechanism for 0.4 V < V < 1.5 V while by the space-charge-limited current conduction beyond 1.5 V. The heterojunction is sensitive to the UV light with the faster rise and decay time constants of 360 and 280 ms, respectively. (c) 2007 American Institute of Physics.