The Gold Nanoparticles Enhanced ZnO/GaN UV Detector

Abstract

Ultraviolet detectors can be used in ultraviolet disinfection, missile guidance and short-wave communication fields. Here we have grown GaN (002) film by chemical vapor deposition (CVD), through depositing 100 nm ZnO film as buffer layers on sapphire substrates by magnetron sputtering. Using Ni as the electrode, the metal-semiconductor-metal (MSM) ultraviolet (UV) detector was prepared. The device dark current, photocurrent and UV on/off current ratio were $5.19 \times 10^{-9}\text{ A}$ , $2.52 \times 10^{-7}\text{A}$ and 54, under 2V bias. Then, using Au nanoparticles as plasmons, the photocurrent and photoresponsivity of the device were increased by 5.32 times and 5.25 times, respectively, and the UV on/off current ratio reached 176. The photoresponsivity of the device reaches the maximum value 0.42A/W at 370nm, the response time and relaxation time reach 0.1s and 0.12s, respectively.

Keywords

• ZnO/GaN film
• UV detector
• Au nanoparticles