Preparation of Sn-doped Ga<sub>2</sub>O<sub>3</sub> thin films and their solar-blind photoelectric detection performance
Lijun Li, Li Chengkun, Shaoqing Wang, Lu Qin, Yifan Jia, Haifeng Chen
Abstract
Abstract Sn doping is an effective way to improve the response rate of Ga 2 O 3 film based solar-blind detectors. In this paper, Sn-doped Ga 2 O 3 films were prepared on a sapphire substrate by radio frequency magnetron sputtering. The films were characterized by X-ray diffraction, scanning electron microscopy, X-ray photoelectron spectroscopy and ultraviolet visible spectroscopy, and the effect of annealing atmosphere on the properties of films was studied. The Ga 2 O 3 films changed from amorphous to β -Ga 2 O 3 after annealing at 900 °C. The films were composed of micro crystalline particles with a diameter of about 5–20 nm. The β -Ga 2 O 3 had high transmittance for wavelengths above 300 nm, and obvious absorption for solar-blind signals at 200–280 nm. The metal semiconductor metal type solar-blind detectors were prepared. The detector based on Sn-doped β -Ga 2 O 3 thin film annealed in N 2 has the best response performance to 254 nm light. The photo-current is 10 μ A at 20 V, the dark-current is 5.76 pA, the photo dark current ratio is 1.7 × 10 6 , the response rate is 12.47 A/W, the external quantum efficiency is 6.09 × 10 3 %, the specific detection rate is 2.61 × 10 12 Jones, the response time and recovery time are 378 and 90 ms, respectively.