Enhanced Performance of Self-Powered Solar-Blind Deep UV Photodetectors Based on ZnGa2O4/Ga2O3 Heterojunctions

• Published in: IEEE sensors journal Vol. 24; no. 11; pp. 17661 - 17668
• Main Authors: Liu, Jia-Hang, Ji, Xue-Qiang, Li, Shan, Liu, Zeng, Lu, Cheng-Ling, Yang, Yong-Tao, Zhang, Fan, Wu, Zhen-Ping, Tang, Wei-Hua
• Format: Journal Article
• Language: English
• Published: New York IEEE 01.06.2024; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Dark current; Gallium oxide (Ga2O3); Gallium oxides; heterojunction; Heterojunctions; Open circuit voltage; Partial discharges; Performance enhancement; Photodetectors; Photometers; Photonic band gap; Photovoltaic effect; self-powered; solar-blind ultraviolet (UV) photodetector (PD); Sputtering; Ultraviolet detectors
• ISSN: 1530-437X; 1558-1748
• DOI: 10.1109/JSEN.2024.3388471

Self-powered ultraviolet (UV) photodetectors (PDs) attract much research attention because of their promising application in solar-blind region detection. Here, a high-performance self-powered PD is constructed using the heterojunction of gallium oxide (Ga2O3) and ZnGa2O4. Taking advantage of the low concentration of oxygen vacancies (Vo) in ZnGa2O4 and the photovoltaic effect at the interface, the PD demonstrates inspiring solar-blind UV photodetection capabilities. Under external bias (5 V), the ZnGa2O4/Ga2O3 heterojunction PD exhibits an ultralow dark current of 0.06 pA, a high photo-dark current ratio (PDCR) of <inline-formula> <tex-math notation="LaTeX">9.39\times 10^{{5}} </tex-math></inline-formula>, and a rapid response speed. In the self-powered mode (0 V), the PD demonstrates a significant photovoltaic effect, which is characterized to have an open-circuit voltage of 0.14 V. Additionally, it exhibits enhanced photoresponse with PDCR of approximately <inline-formula> <tex-math notation="LaTeX">10^{{4}} </tex-math></inline-formula> (<inline-formula> <tex-math notation="LaTeX">500~\mu </tex-math></inline-formula>W/cm<inline-formula> <tex-math notation="LaTeX">^{{2}}\text {)} </tex-math></inline-formula>. Our findings suggest that ZnGa2O4/Ga2O3 heterojunction PDs can potentially become a highly efficient and energy-saving option for solar-blind detection in the future.