Radiation Hardness of an α-Ga₂O₃ Nanorod Array/FTO Solar-Blind Photodetector Against the 50-MeV Proton Beam

Radiation hardness of one
$\alpha $
-gallium oxide (Ga2O3) nanorod array/FTO solar-blind photodetector against 50-MeV protons was tested at the Huairou Proton Cyclotron, China. The
$\alpha $
-Ga2O3 nanorod array/FTO samples were first subjected to proton irradiation with a fluence up to
$5 \times 10^{13} \, \rm {p}/\rm {cm}^{2}$
and then used as the photoanode, and the photoelectrochemical properties, including the light current, dark current, and responsivity, were measured. We demonstrate that the responsivity of the photodetector at 0 V is 37% declined at
$5 \times 10^{12} \, \rm {p}/\rm {cm}^{2}$
proton fluence. The photodetector can be still used to detect the UV light after 50-MeV proton irradiations with a fluence of
$5 \times 10^{12} \, \rm {p}/\rm {cm}^{2}$
, implying its potential applications in space. The damage mechanism of the
$\alpha $
-Ga2O3 nanorod array/FTO samples due to proton irradiation is then analyzed using the stopping-and-range-of-ions-in-matter and transport of ions in matter (SRIM and TRIM) code, which indicates that both the ionization and displacement damage contribute to the responsivity degradation.