Solar-Blind Ultraviolet Detectors Based on High-Quality HVPE α-Ga <sub>2</sub> O <sub>3</sub> Films With Giant Responsivity
А. V. Аlmaev, В. И. Николаев, V. V. Kopyev, Sevastian Shapenkov, Nikita N. Yakovlev, Bogdan O. Kushnarev, Aleksei Pechnikov, Jinxiang Deng, T. I. Izaak, Àndrei Chikiryaka, M. P. Scheglov, Anton Zarichny
Abstract
The MSM structures based on high-quality 1.6- <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\mu \text{m}$ </tex-math></inline-formula> -thick <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\alpha $ </tex-math></inline-formula> -gallium oxide (Ga2O3) films grown by the halide vapor phase epitaxy with Ti/Ni interdigital contacts were developed for the detection of short-wave ultraviolet (UVC) radiation. The spectral dependences of responsivity, external quantum efficiency (EQE), and detectivity of MSM structures based on <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\alpha $ </tex-math></inline-formula> -Ga2O3 were studied in the wavelength range of 205–260 nm. The responsivity, the EQE, and the detectivity are <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$7.19\times104$ </tex-math></inline-formula> A <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\times \,\,\text{W}^{-{1}}$ </tex-math></inline-formula> , <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$3.79\times105$ </tex-math></inline-formula> arb.un., and <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$1.12\times1018$ </tex-math></inline-formula> Hz <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$^{\text {0.{5}}} \times $ </tex-math></inline-formula> cm <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\times \,\,\text{W}^{-{1}}$ </tex-math></inline-formula> , respectively, for structures with an interelectrode distance of 30 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\mu \text{m}$ </tex-math></inline-formula> 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 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\alpha $ </tex-math></inline-formula> -Ga2O3. The prospects of researches to develop UVC radiation detectors for wireless UVC communication were shown.