Room temperature fabrication and post-annealing treatment of amorphous Ga 2 O 3 photodetectors for deep-ultraviolet light detection

This work fabricates deep-ultraviolet (DUV) photodetectors (PDs) with a metal-semiconductor-metal structure based on radio-frequency sputtered amorphous Ga 2 O 3 films at room temperature. The Ga 2 O 3 -based PD exhibits a low dark current of 1.41 × 10 −11 A, a responsivity of 1.77 A W −1 and a fast rise response time of 114 ms. A series of annealing treatments with different atmospheres have been found effective to reduce the oxygen vacancy concentration, exhibiting a trade-off effect between the responsivity and the response time. These results demonstrate a cost-effective room-temperature approach for fabricating amorphous Ga 2 O 3 -based PDs and developing possible post-synthetic methods for tuning the PD performance.