Nano Science and Nano Technology Program, The Hong Kong University of Science and Technology, HKSAR, People's Republic of China
Wai-Yip Cheung
Department of Physics and William Mong Institute of Nano Science and Technology, The Hong Kong University of Science and Technology, HKSAR, People's Republic of China
Shu-Kin Lok
Department of Physics and William Mong Institute of Nano Science and Technology, The Hong Kong University of Science and Technology, HKSAR, People's Republic of China
George K. L. Wong
Department of Physics and William Mong Institute of Nano Science and Technology, The Hong Kong University of Science and Technology, HKSAR, People's Republic of China
Sut-Kam Ho
Faculty of Science and Technology, University of Macau, Macau, People's Republic of China
Kam-Weng Tam
Department of Electrical and Computer Engineering, University of Macau, Macau, People's Republic of China
Iam-Keong Sou
Department of Physics and William Mong Institute of Nano Science and Technology, The Hong Kong University of Science and Technology, HKSAR, People's Republic of China
Studies using in-situ Auger electron spectroscopy and reflection high energy electron diffraction, and ex-situ high resolution X-ray diffraction and electron backscatter diffraction reveal that a MgS thin film grown directly on a GaAs (100) substrate by molecular beam epitaxy adopts its most stable phase, the rocksalt structure, with a lattice constant of 5.20 Å. A Au/MgS/n+-GaAs (100) Schottky-barrier photodiode was fabricated and its room temperature photoresponse was measured to have a sharp fall-off edge at 235 nm with rejection of more than three orders at 400 nm and higher than five orders at 500 nm, promising for various solar-blind UV detection applications.
