Fast-response self-powered solar-blind photodetector based on Pt/β-Ga2O3 Schottky barrier diodes

Abstract A Schottky barrier diode solar-blind photodetector was fabricated on single crystal β -Ga2O3. Optoelectronic tests at 254 nm have shown that the detector has the maximum ratio (nearly 1 × 104) of light to dark current at zero voltage bias, indicating that the detector can work without any external energy (self-powered action). A fast response speed of the detector has also been found, while the rise and decay time are only 65 ms and 15 ms at self-powered mode, respectively. With increasing the illumination intensity, the photocurrent of the device is enhanced linearly, maintaining the fast response speed. Under a large fixed bias, the photoresponse time turns to be longer comparing with that at zero voltage, which can be attributed to the electrons and holes captured by the oxygen vacancies being released gradually under an applied bias. In addition, the mechanism of this self-powered photodetector has been explained by understanding the motion of photo-generated carrier.