Lim, Namsoo Min, Jungwook Min, Jung-Hong Kang, Chun Hong Li, Kuang-Hui Park, Tae -Yong Kim, Woochul Davaasuren, Bambar Ng, Tien Khee Ooi, Boon S. Ha Woo, Deok Park, Ji-Hyeon Pak, Yusin 2024-01-19T10:31:45Z 2024-01-19T10:31:45Z 2022-12-01 2023-01 0169-4332 https://pubs.kist.re.kr/handle/201004/114181 Orthorhombic kappa-Ga2O3, as one of the Ga2O3 polymorphs, is considered a promising as ultrawide bandgap material for extreme environment devices. It is considered more superior than the conventional group III-V compound semiconductors and silicon carbides in extreme environments demanding material/device characteristics of high-voltage, high-temperature, high-pressure, high-impact, and high-radiation. In this study, we demonstrate ultrasensitive ultraviolet-C (UV-C) detection using Si-doped orthorhombic kappa-Ga2O3 photodetectors. A 150 nm thick kappa-Ga2O3 film was grown on a 2-inch diameter sapphire (a-Al2O3) wafer via metal organic chemical vapor deposition (MOCVD) method. The crystallinity of orthorhombic kappa-Ga2O3 film was investigated by X-ray diffraction (XRD) and transmission electron micro-scopy (TEM). The ultrawide bandgap of approximately 4.9 eV was confirmed by UV transmittance measurement. For UV-C detection analysis, a planar device with a channel length of 20 mu m was fabricated using Au/Ti metal contacts on the orthorhombic kappa-Ga2O3 film. The device doped under 15 sccm SiH4 flow rate showed ultrahigh photoresponse of similar to 72.1 A/W, I-on/I-off of-14, and decent rise ( similar to 0.35 s) and decay (similar to 1.79 s). Our results will contribute to the understanding on a new material phase of kappa-Ga2O3, as well as on developing optoelectronics devices with high radiation hardness suitable for operation in extreme environments. English Elsevier BV Ultrasensitive UV-C detection based on MOCVD-grown highly crystalline ultrawide bandgap orthorhombic κ-Ga2O3 Article 10.1016/j.apsusc.2022.155350 1 Applied Surface Science, v.609 Applied Surface Science 609 Y scie scopus 000882457200005 Chemistry, Physical Materials Science, Coatings & Films Physics, Applied Physics, Condensed Matter Chemistry Materials Science Physics Article SOLAR-BLIND PHOTODETECTORS BETA-GA2O3 THIN-FILMS ULTRAVIOLET PHOTODETECTOR EPSILON-GA2O3 FABRICATION SAPPHIRE