Photoresponsivity of p-GaN HEMT-based ultraviolet photodetectors at low temperatures

In this work, we carried out research on the photoresponsivity of a high-performance p-GaN high-electron mobility transistor-based ultraviolet photodetector at low temperatures. The device exhibited an extraordinary responsivity of 2.8 × 106 A/W at 100 K, demonstrating its great potential in frigid environment. Meanwhile, the mechanism of interaction between photo-generated carriers and defects is also discussed. The quantitative analysis of the decay behavior reveals that two trap levels determined the decay behavior in different temperature intervals. It provides constructive evidence for understanding the persistent photoconductivity behavior and can be meaningful in further improvement of the device performance.