Solar-blind ultraviolet detectors based on high-quality HVPE α-Ga2O3 films with giant responsivity

The MSM structures based on high-quality 1.6 μm in thick α-Ga 2 O 3 films grown by the halide vapor phase epitaxy with Ti/Ni interdigital contacts were developed for detection of short-wave ultraviolet (UVC) radiation. The spectral dependences of responsivity, external quantum efficiency and detectivity of MSM structures based on α-Ga 2 O 3 were studied in the wavelength range of 205-260 nm. The responsivity, the external quantum efficiency and the detectivity are 7.19×10 4 A×W -1 , 3.79×10 5 arb.un. and 1.12×10 18 Hz 0.5 ×cm×W -1 , respectively, for structures with an interelectrode distance of 30 μm at an applied voltage of 10 V and exposure to radiation with a wavelength of 235 nm. The high values of the photoelectric characteristics were caused by the manifestation of an internal gain of the photoresponse due to the self-localization of holes in α-Ga 2 O 3 . The prospects of researches to develop UVC radiation detectors for wireless UVC communication were shown.