【Domestic Papers】Researchers from the Fujian Normal University on High-performance a-Ga₂O₃ solar-blind photodetectors by pulsed magnetron sputtering deposition

      Researchers from the Fujian Normal University have published a dissertation titled "High-performance a-Ga₂O₃ solar-blind photodetectors by pulsed magnetron sputtering deposition" in Journal of Vacuum Science & Technology A.

ABSTRACT

      Solar-blind photodetectors (SBPDs) based on the ultrawide-bandgap semiconductor Ga₂O₃ have gained attention due to their potential applications in both military and civilian domains. As technology advances, photodetectors are being improved to achieve better energy efficiency, smaller size, and better performance. Solar-blind photodetectors based on a metal-semiconductor-metal structure of amorphous gallium oxide (a-Ga₂O₃) films were fabricated by pulsed magnetron sputtering deposition (PSD). The photodetector based on amorphous gallium oxide has a responsivity of 71.52 A/W, a fast rising and falling response time of less than 200 ms, a photo-to-dark current ratio (PDCR) of 6.52 × 10⁴, and an external quantum efficiency of 34 526.62%. PSD-prepared gallium oxide SBPDs demonstrate a cost-effective room temperature method for growing gallium oxide and show the advantages of growing gallium oxide.

FIG. 1.(a) SEM image of S37 at 500 nm. (b) 2D surface morphology images of AFM at 1 × 1 μm², and the root-mean-square (RMS) roughness of the S37 (RMS = 0.32 nm). (c) XRD patterns of S19, S28, S37, and S47. (d) 3D surface morphology images of AFM at 1 × 1 μm² and the root-mean-square (RMS) of the S37. (e) Transmittance spectra of S19, S28, S37, and S47. (f) Optical bandgap diagram of S19, S28, S37, and S46 calculated from the Tauc-plot formula.

FIG. 2. (a)–(d) I-V plots (-20∼20 V) of S19, S28, S37, and S46 in dark and ultraviolet illumination at 248, 256, 257, and 248 nm respectively. (e) Relationship between the responsivity and wavelength for different devices of S19, S28, S37, and S46 at 20 V and the peak wavelength as well as the responsivity for each device. (f) Photocurrent vs time for different devices of S19, S28, S37, and S46 irradiated with different wavelengths of ultraviolet light for the circle of 30 s.

FIG. 3.(a) Survey of different samples in the x-ray photoelectron spectrometer (XPS). (b) Ga2p 1/2 and Ga2p 3/2 of different samples. (c) Peak fitting of the atomic energy spectrum of O1s of the S19. (d) Peak fitting of the atomic energy spectrum of Ga2p 3/2 of S19.

Paper Link：https://doi.org/10.1116/6.0003442