High Responsivity Mg_xZn_1-xO Film UV Photodetector Grown by RF Sputtering

This letter focused on Mg_xZn_1-xO thin films grown on quartz substrates using radio frequency magnetron sputtering. The films were then used to fabricate metal-semiconductor-metal ultraviolet (UV) photodetectors (PDs) with different flow rates of argon gas (30, 25, and 20 sccm) and oxygen gas (0, 5, and 10 sccm). We obtained the best parameters for the 25:5 sccm gas flow Mg_xZn_1-xO UV PD. The samples' Mg content was relatively high, contributing to low dark current. Furthermore, the oxygen flow rate for 5 sccm was manipulated properly, so the film was more conductive, having a maximum responsivity of 2.133 A/W with 280-nm illumination and 10 V applied bias. The maximum photocurrent was 1.3 μA, and the device's ON/OFF current switching characteristic was very stable.