In this study, beta-Ga2O3/n-Si isotype heterojunction was fabricated to form a solar-blind ultraviolet photodetector by depositing beta-Ga2O3 film on n-type Si substrate using metal-organic chemical vapor deposition. Photodetection properties of the photodetector were investigated systematically. The fabricated isotype heterojunction photo detector exhibited typical rectifying characteristics and excellent light on-off switching performance. Under 254 nm illumination, the photodetector showed the photo-to-dark current ratio of 591.38 at-20 V bias. Meanwhile, fast response speed with rise time (tau(r1), tau(r2)) of (0.20 s, 1.81 s) and decay time (tau(d1), tau(d2)) of (0.02 s, 5.12 s) at -20 V bias was obtained. The results indicate that the photodetector based on beta-Ga2O3/n-Si isotype heterojunction has excellent sensitivity and selectivity to solar-blind ultraviolet light.

A solar-blind ultraviolet photodetector based on p-Si/n-beta-Ga2O3:Si heterojunction, using the Si-doped beta-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-beta-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 (tau(r1), tau(r2)) and the decay time constants (tau(d1), tau(d2)) 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-beta-Ga2O3:Si heterojunction photodetector displayed relatively faster response speed compared to the reported photodetectors based on p-Si/undoped beta-Ga2O3 heterojunction. The results indicate that photodetectors based on p-Si/n-beta-Ga2O3:Si heterojunction have potential development for the high-performance solar-blind ultraviolet photodetectors.

Eu3+-doped ZnMoO4 red phosphors with different doping concentrations were synthesized at the temperature of 800 °C by solid-state reaction technique in air atmosphere. The structures of the phosphors were characterized by X-ray diffraction and Raman spectra. The excitation and emission spectra were used to investigate the photoluminescent properties of the phosphors. The effect of Eu3+ concentration on the structural and photoluminescent properties of ZnMoO4:Eu3+ red phosphors were discussed systemically. And the photoluminescent properties of ZnMoO4:Eu3+ red phosphors under different excitation wavelengths were investigated to find their utilities in various lighting applications. Strong red emission intensity and high color purity with chromaticity coordinates (0.666, 0.334) were obtained for Zn0.8MoO4:0.2Eu3+ phosphors excited at 395 nm. The Zn1−xMoO4:xEu3+ phosphors, which could be applied as red-emitting phosphors excited by ultra-violet and blue chips, have potential application in white light-emitting diodes.