Fabrication and properties of a solar-blind ultraviolet photodetector based on Si-doped β-Ga2O3 film grown on p-Si (111) substrate by MOCVD

Abstract A solar-blind ultraviolet photodetector based on p-Si/n-β-Ga2O3:Si heterojunction, using the Si-doped β-Ga2O3 as the n-type layer, was fabricated successfully by metal-organic chemical vapor deposition (MOCVD). The current-voltage and photoresponse characteristics of photodetector were investigated. The fabricated p-Si/n-β-Ga2O3:Si heterojunction photodetector exhibited typical rectification behavior and good solar-blind ultraviolet photoresponse. Sensitive photodetection of current at the reverse bias voltage and stable on-off switching performance were achieved. The photodetector showed a responsivity of 3.76 A/W and a photo-to-dark current ratio of 37.9 under 254 nm illumination. The rise time constants ( τ r 1 , τ r 2 ) and the decay time constants ( τ d 1 , τ d 2 ) of the photodetector under 254 nm illumination at the reverse voltage of − 20 V were estimated to be (0.30 s, 0.76 s) and (0.15 s, 6.15 s), respectively. The fabricated p-Si/n-β-Ga2O3:Si heterojunction photodetector displayed relatively faster response speed compared to the reported photodetectors based on p-Si/undoped β-Ga2O3 heterojunction. The results indicate that photodetectors based on p-Si/n-β-Ga2O3:Si heterojunction have potential development for the high-performance solar-blind ultraviolet photodetectors.