Self-Powered p-GaN/i-ZnGa₂O₄/n-ITO Heterojunction Broadband Ultraviolet Photodetector With High Working Temperature

A self-driven p-GaN/i-ZnGa2O4/n-ITO heterojunction broadband ultraviolet (BUV) photodetector was firstly demonstrated in this work with a high working temperature. In the 25–300 °C temperature range, the device exhibits excellent and stable BUV photodetection performance. Even at 300 °C, a large peak responsivity of ~132 mA/W, a broad UV response band ranging from 250 to 400 nm, a high UV-to-visible rejection ratio of nearly 104, and a high −3 dB cutoff frequency of 20 kHz can be still observed at 0 V, which is obviously superior to the other reported high-temperature BUV heterojunction photodetectors. The remarkable performance of our device at high temperature can be attributed to the excellent insulation and high crystalline quality of i-ZnGa2O4 layer, as well as the good electrical properties of p-GaN and n-ITO. Moreover, their wide and complementary band gaps make the device have a very broad UV detection band.