Enhancing ultraviolet response of NiO/Si heterojunction by high temperature anneal

In this work, NiO/Si heterojunction is fabricated by direct current reactive magnetron sputtering process and the effect of post anneal temperature on ultraviolet response of the heterojunction is investigated. The results indicate that the dark current is decreased and the light current is increased with annealing temperature increasing in the fabricated NiO/Si heterojucntion. When illuminated under 365 nm UV light with an intensity of 1.0 mW/cm2, the light to dark switch ratio of the fabricated NiO/Si heterojunction annealed at 800 °C is about 486.1. The corresponding ultraviolet response is enhanced by about 83.8 times compared to the heterojucntion without anneal. The switch-on and switch-off time of the 800 °C annealed NiO/Si heterojunction illuminated under 365 nm UV light are about 100 μs and 180 μs, respectively. It is expected that the NiO/Si heterojunction has enormous potential in multi-wavelength light detecting application.