Boosting Solar Blind UV Detector by Constructing Enhanced-Mode MOS Field-Effect Transistors based on β-Ga2O3 Film

• Published in: IEEE sensors journal Vol. 23; no. 19; p. 1
• Main Authors: Ji, Xue-Qiang, Lu, Chao, Wang, Jin-Jin, Li, Meng-Cheng, Qi, Xiao-Hui, Yue, Jian-Ying, Shu, Lei, Li, Pei-Gang
• Format: Journal Article
• Language: English
• Published: New York IEEE 01.10.2023; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Dark current; FET; Field effect transistors; Film thickness; Gallium; Gallium oxide (Ga<sub xmlns:ali="http://www.niso.org/schemas/ali/1.0/" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">2 O<sub xmlns:ali="http://www.niso.org/schemas/ali/1.0/" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">3 ); Gallium oxides; gate modulation; Incident light; Logic gates; Luminous intensity; MOS devices; MOSFETs; Performance evaluation; Photoconductivity; Photoelectric effect; Photoelectricity; Semiconductor devices; Sensors; solar-blind UV photodetector; Substrates; Ultraviolet detectors
• ISSN: 1530-437X; 1558-1748
• DOI: 10.1109/JSEN.2023.3305772

A three-terminal metal-oxide field-effect transistor (MOSFET) switching device is an exciting solution for achieving low dark currents and high photocurrents. The back-gated structure effectively ensures the full exposure of the top layer of β-Ga 2 O 3 to incident light, thereby maximizing the collection of detection information. In this study, we achieved an enhanced mode back-gated MOSFET based on β-Ga 2 O 3 film for Solar-Blind UV detection applications with a film thickness of 80 nm. Compared to the traditional two-terminal structure, the MOS device's channel was fully depleted via gate modulation, resulting in a further reduction of the intrinsic dark current. Meanwhile, the photoconductivity performance is greatly improved through the dual regulation mode of light intensity and gate voltage. As a consequence, the back-gated MOS photodetector shows a much superior photoelectric performance, characterized by an ultralow dark current of 0.018 pA and a high photo-to-dark current ratio of 6.7 × 10 4 . Our findings suggest that utilizing an E-mode back-gated MOS structure could serve as a highly efficient and energy-saving approach for the development of Ga 2 O 3 photodetectors in solar-blind UV applications.