LAUSR

We have optimized the responsivity and response speed of a β-Ga2O3-based photodetector. The β-Ga2O3thin films were deposited on a glass substrate under various oxygen partial pressures from 0 to 50 mTorr by pulsed laser deposition. Time-response measurements show that the as-grown β-Ga2O3at an oxygen partial pressure of 50 mTorr has the fastest response speed and decay times of 33 and 100 ms, which are better than those prepared at lower oxygen pressures. This sample also showed a high photoresponsivity of 5 A/W and the detectivity of 1012cmHz1/2W. The high performance of the β-Ga2O3detector grown at the oxygen partial pressure of 50 mTorr might be due to the reduction of oxygen vacancies by increasing oxygen during the deposition. The results reveal the importance of the oxygen processing gas in promoting photodetector performance.