Ahn, Jungho Ma, Jiyeon Lee, Doeon Lin, Qiubao Park, Youngseo Lee, Oukjae Sim, Sangwan Lee, Kyusang Yoo, Geonwook Heo, Junseok 2024-01-19T15:30:52Z 2024-01-19T15:30:52Z 2021-09-02 2021-02-17 2330-4022 https://pubs.kist.re.kr/handle/201004/117392 Deep-ultraviolet (DUV) photodetectors based on wide-band-gap semiconductors have attracted significant interest across a wide range of applications in the industrial, biological, environmental, and military fields due to their solar-blind nature. As one of the most promising wide-band-gap materials, beta-Ga2O3 provides great application potential over detection wavelengths ranging from 230 to 280 nm owing to its superior optoelectronic performance, stability, and compatibility with conventional fabrication techniques. Although various innovative approaches and device configurations have been applied to achieve highly performing beta-Ga2O3 DUV photodetectors, the highest demonstrated responsivity of the beta-Ga2O3 photodetectors has only been around 10(5) A/W. Here, we demonstrate a beta-Ga2O3 phototransistor with an ultrahigh responsivity of 2.4 x 10(7) A/W and a specific detectivity of 1.7 x 10(15) Jones, achieved by engineering a photogating effect. A beta-Ga2O3/MgO heterostructure with an Al2O3 encapsulation layer is employed not only to reduce photogenerated electron/hole recombination but also to suppress the photoconducting effects at the back-channel surface of the beta-Ga2O3 phototransistor via a defect-assisted charge transfer mechanism. The measured photoresponsivity is almost 2 orders of magnitude higher than the highest previously reported value in a beta-Ga2O3-based photodetector, to the best of our knowledge. We believe that the demonstrated beta-Ga2O3/MgO heterostructure configuration, combined with its facile fabrication method, will pave the way for the development of ultrasensitive DUV photodetectors utilizing oxide-based wide-band-gap materials. English AMER CHEMICAL SOC Ultrahigh Deep-Ultraviolet Responsivity of a beta-Ga2O3/MgO Heterostructure-Based Phototransistor Article 10.1021/acsphotonics.0c01579 1 ACS PHOTONICS, v.8, no.2, pp.557 - 566 ACS PHOTONICS 8 2 557 566 scie scopus 000621063700023 2-s2.0-85099907262 Nanoscience & Nanotechnology Materials Science, Multidisciplinary Optics Physics, Applied Physics, Condensed Matter Science & Technology - Other Topics Materials Science Optics Physics Article BLIND PHOTODETECTORS MGXZN1-XO GRAPHENE LAYER beta-Ga2O3 photogating effect phototransistor charge transfer deep ultraviolet ultrahigh responsivity