Influence of High-Dose 80 MeV Proton Irradiation on the Electronic Structure and Photoluminescence of β-Ga2O3

beta-Ga2O3 is regarded as one of the best materials for application in deep space exploration; thus, research on beta-Ga2O3-related radiation damage is necessary for the use of devices in harsh environments. The present work explored the effects of 80 MeV high-energy proton irradiation on beta-Ga2O3 single crystals with fluence of 4 x 10(13) cm(-2) and 1 x 10(14) cm(-2). X-ray photoelectron spectrometry (XPS) and ultraviolet photoelectron spectrometry (UPS) measurements demonstrated that before proton irradiation, the Fermi level was pinned at the mid-gap energy level due to the existence of native oxygen and gallium vacancy defects. After proton irradiation, gallium and oxygen vacancies increased with irradiation fluence, resulting in the reduction of the bandgap of beta-Ga2O3. Proton irradiation of beta-Ga2O3 at 80 MeV is more likely to produce oxygen vacancies; hence, the Fermi level shifts upward to the conduction band. In addition, the UV photoluminescence emission at 3.29 eV is greatly enhanced with irradiation fluence. These results will be helpful for the design of UV devices. [Graphics]

Automated summary

This study investigates the effects of 80 MeV high-energy proton irradiation on beta-Ga2O3 single crystals. It is found that irradiation increases gallium and oxygen vacancies, resulting in a reduction of the bandgap. Proton irradiation at 80 MeV is more likely to produce oxygen vacancies, causing the Fermi level to shift upward to the conduction band, and enhancing UV photoluminescence emission.