Electron beam irradiation studies of ZnGa2O4:Mn2+ green phosphor

Abstract The surface composition and stability of ZnGa2O4:Mn2+ green phosphor were evaluated using Auger electron spectroscopy (AES) under electron beam irradiation in vacuum and oxygen (4.0 × 10−7 mbar). The surface chemistry was monitored while measuring the cathodoluminescence (CL) intensity. The Auger peak-to-peak heights (APPHs) of Zn and Ga were stable during irradiation in vacuum for a beam current of 1 μA, whereas the APPH of Ga initially slightly increased during irradiation in vacuum and oxygen for a beam current of 3 μA. This was accompanied with a slight initial decrease of C contamination. The APPH of O decreased during irradiation in vacuum for a beam current of 3 μA, whereas it slightly increased during irradiation in oxygen. In vacuum the CL intensity exhibited a slight initial decrease during irradiation, after which it recovered and stabilized, whereas in oxygen the CL intensity decreased initially and then stabilized. The profile of the CL spectra did not show noticeable changes as a result of irradiation. TL measurements showed that the ZnGa2O4:Mn2+ activated with UV or e-beam exhibited two broad peaks. The differences were attributed to the change in concentrations of Zn and O vacancies that could be caused by e-beam irradiation.