Single ZnO Microrod Ultraviolet Photodetector with High Photocurrent Gain

摘要

An Ag/ZnO microrod/Ag ultraviolet photodetector is fabricated, the ZnO microrod shows a hexagonal whispering gallery cavity structure. Upon a 325 nm ultraviolet illumination, the device shows a high sensitivity of 4 × 10~4 A/W and a high photocurrent gain of 1,5 × 10~5 at 5 V bias. Under different illumination power P, the photocurrent I_(light) obeys a power law relation I_(light) ∝ P~(0.69). The high performance is probably attributed to a Schottky barrier at Ag/ZnO interface and optical whispering gallery mode effect in the ZnO microrod.