Influence of Oxygen Vacancy and Metal–semiconductor Contact on the Device Performance of Amorphous Gallium Oxide Photodetectors

Here we investigate the influence of the oxygen vacancy content and the electrode contact on the performance of deep ultraviolet photodetectors based on amorphous Ga2O3 films. The fine-tuning of the oxygen ratio effectively reduces the oxygen vacancy content, which obtains optimized device performance with a responsivity of 5.78 A W−1 and a rise/fall time of 301/89 ms. The metal contact formation and its impact on the device performance are further studied. Compared to the Ohmic-type device using Ti electrodes, the Schottky-type devices using Au and Al electrodes exhibit a shorter rise time and a lower dark current.