GaN MSM UV Detectors With Different Electrode Materials

The different electrode (In-In, Ni-Ni, Ni-In) MSM ultraviolet photodetectors were fabricated on GaN thin film which is grown on sapphire. The test result of the three electrode detectors show that the dark current of In-In device and Ni-Ni device are in the order of $10 ^{-8}\text{A}$ and $10 ^{-9}\text{A}$ , respectively, at bias of 5-10V. Asymmetric electrode (Ni-In) device has asymmetry dark current and a larger photocurrent than the symmetrical electrode devices. At the same time, Ni-In devices have a self-powered effect, under 0V bias, the photocurrent reaches $8\times 10 ^{-9}\text{A}$ , and the photoresponse is 5.4mA/W at 360nm.