GaN MSM Photodetectors With a Semi-Insulating Mg-Doped AlInN Cap Layer

We report the fabrication of GaN-based ultraviolet (UV) metal-semiconductor-metal photodetectors with a semi-insulating AlInN cap layer. It was found that we can achieve a smaller dark leakage current, a larger UV-to-visible rejection ratio, a smaller noise level, and a larger detectivity while maintaining the sharp transition by inserting the semi-insulating AlInN cap layer.