Solar-blind UV photoelectric properties of pure-phase α-Ga2O3 deposited on m-plane sapphire substrate

a-Ga2O3 film deposited on m-plane sapphire substrate by RF magnetron sputtering method was used to fabricate a solar-blind UV PD with traditional MSM structure. The optimum deposition temperature of the pure-phase (300) a-Ga2O3 film was confirmed to be 775 celcius from the XRD, AFM and deposition rate analyses. The bandgap of the prepared a-Ga2O3 film was estimated to be 5.3 eV from the optical absorbance measurement. The (300) a-Ga2O3 film based PD exhibited a responsivity of 659.6 A/W and a photo-to-dark ratio of 1554 under 254 nm light illumination. The response time constants at bias voltage of 5 V were estimated to be (0.28, 1.52 s) and (0.04, 0.62 s), respectively.

Automated summary

A solar-blind UV photodetector (PD) with a traditional MSM structure was fabricated using an a-Ga2O3 film deposited on an m-plane sapphire substrate by RF magnetron sputtering method. The optimum deposition temperature for the pure-phase (300) a-Ga2O3 film was determined to be 775°C based on XRD, AFM, and deposition rate analyses. The bandgap of the prepared a-Ga2O3 film was found to be 5.3 eV through optical absorbance measurement. The (300) a-Ga2O3 film based PD exhibited a responsivity of 659.6 A/W and a photo-to-dark ratio of 1554 under 254 nm light illumination. The response time constants at a bias voltage of 5 V were estimated to be (0.28, 1.52 s) and (0.04, 0.62 s), respectively.