Solar-blind ultraviolet detector based on ordered nanoporous β -Ga 2 O 3 film

Abstract The β -Ga 2 O 3 ultraviolet (UV) detectors work in the solar-blind (UV) band due to the ultra-wide bandgap of β -Ga 2 O 3 . In this paper, a solar-blind ultraviolet detector based on an ordered nanoporous β -Ga 2 O 3 (ONP- β -Ga 2 O 3 ) film is proposed and implemented. The local enhancement effect of the ordered nanopores on light is simulated by finite-difference time-domain method, and the period and diameter of the nanopores are optimized. Graphene is transferred on the ONP- β -Ga 2 O 3 film and prepared as interdigital electrodes of the solar-blind ultraviolet detectors. The optimal detector has a photo-to-dark current ratio of about 4.64 × 10 3 at a 5 V bias, a peak response of 2.43 A W −1 at 254 nm, and a UV/visible rejection ratio of about 1081. We demonstrate that the ordered nanoporous structure can localize optical field effectively, which results in enhancement of light absorption as well as improvement of key detector parameters.