Fig. 3

a Schematic diagram showing the device structure consisting of ITO/NiO/β-Ga₂O₃/Al. b Energy band diagram of the photodetector. c–d Measured J-V and log J-V curves, respectively, of the photodetector illuminated with a light of different wavelengths, and under dark conditions. e–f Measured J-V and log J-V curves, respectively, of the photodetector under an UV illumination of 245 nm with different power density. g–h Responsivity (R) and detectivity (D*), respectively, of the photodetector at different bias voltages under 245 nm light illumination