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 IF∕IR of 33 at 5V. The current transport is dominated by the recombination-tunneling mechanism for 0.4V<V<1.5V while by the space-charge-limited current conduction beyond 1.5V. The heterojunction is sensitive to the UV light with the faster rise and decay time constants of 360 and 280ms, respectively.