Radiation damage in Ga2O3

The β-phase is the most common of the different polymorphs of Ga2O3 and is stable through the whole temperature range up to the melting point. β-Ga2O3 has a C-centered monoclinic unit cell with space group C2/m. Large diameter bulk crystals of this material are commercially available and the wide bandgap makes it promising for both power electronics and solar-blind UV detection. In some applications, it is desirable that the Ga2O3 have a significant degree of radiation hardness. There are now some initial reports of the effect of proton, electron, gamma ray and neutron irradiation of n-type β-Ga2O3 rectifiers, and UV photodetectors under conditions relevant to low Earth orbit of satellites containing these types of devices. The carrier removal rates for proton, electron, and neutron irradiation are found to comparable to those in GaN of similar doping levels for the same types of fluences. The main defect created in Ga2O3 by proton irradiation has been identified as a Ga vacancy with two hydrogens attached. Neutron irradiation produces a dominant state with an ionization level near EC—1.88 eV.