Low temperature annealed ZnO film UV photodetector with fast photoresponse

- Low temperature annealing process is potential in flexible photodetector application.
- Fast photoresponse of 0.82 ms is obtained in ZnO photoconductive UV detector.
- The working temperature of ZnO UV photodetector should be lower than 150 °C.

Zinc oxide thin film UV photodetectors based metal-semiconductor-metal structure were fabricated on Au interdigital electrodes by radio frequency magnetron sputtering. The performances of the UV photodetector under different annealing and testing temperatures from RT to 200 °C have been studied, obtaining optimized annealing temperature and suitable working temperature range. The detailed photoresponse mechanism has been discussed by analyzing competitive behaviors of several factors. The photodetector has good photoresponse linearity across a wide range of incident light intensity, and the response time, recovery time and responsivity were 0.82 ms, 0.64 ms and 124 A/W respectively under the 2.5 mW/cm2 at 5 V applied bias. The low annealing temperature of ZnO film makes it be applied in flexible photodetector with great potential.