Novel fabrication of UV photodetector based on ZnO nanowire/p-GaN heterojunction

Vertical well-aligned zinc oxide (ZnO) nanowires were grown on p-GaN/ sapphire to produce a p–n heterojunction using the vapor–liquid–solid (VLS) process. A p–n heterojunction in an ultraviolet photodetector was successfully demonstrated. The length of ZnO nanowires on the p-GaN epilayer was in the range 0.7–1 μm and the diameter was in the range 80–100 nm. The current–voltage curve of the heterojunction demonstrates obvious rectifying diode behavior in a dark environment. Under UV light (365 nm), the current was almost 15 times that in the dark current at −5 V. Continuous measurements indicate the reproducibility and stability of this heterojunction photodetector.