Photoresponse and low-frequency noise in RF-sputtered β-Ga2O3 MSM photodetectors for UV-C detection

This is the authors' abstract. We don't add key points for this paper.

RF-sputtered Ga 2 O 3 thin films on sapphire were annealed in air at 500-800 °C for UV-C MSM photodetectors. This study establishes a correlation between annealing-induced oxygen-vacancy modulation and low-frequency noise-limited detection. Annealing at 800 °C improved crystallinity, reduced the XRD peak FWHM from 0.577° to 0.395°, decreased the oxygen-vacancy-related O 1 s contribution from 60.4% to 50.9%, and suppressed the dark current from 1.72 × 10 -5 for the 600 °C device to 6.61 × 10 -9 A for the 800 °C device at 5 V. While the 600 °C device showed higher responsivity due to defect-assisted gain, the 800 °C device exhibited lower noise, with the dominant noise behavior evolving from 1/f noise to a Lorentzian generation-recombination component. As a result, the 800 °C device achieved a noise-equivalent power of 2.71 × 10 -12 W and a specific detectivity of 1.17 × 10 12 cm Hz¹/² W⁻¹, highlighting annealing-controlled defect modulation as an effective route for high-detectivity Ga 2 O 3 UV-C photodetectors.