Optical damage assessment and recovery investigation of hydrogen-ion and deuterium-ion plasma-irradiated bulk ZnO single crystals

In realizing zinc oxide (ZnO) scintillator applications, we assess the optical damage and investigate the recovery of hydrogen-ion (H-ion) and deuterium-ion (D-ion) plasma-irradiated bulk ZnO single crystals. Hydrothermal-grown bulk crystals are irradiated with H-ion and D-ion beams with 1 keV energy and ∼ 10 20 m − 2 s − 1 flux. After irradiation, the single crystals exhibit decreased visible transparencies, redshifted ultraviolet (UV) emission peaks, shortened UV emission lifetimes, and suppressed visible emission bands. These changes in the optical transmittances and photoluminescence emissions are attributed to the generation of defects during irradiation and to the interaction of hydrogen with other defects and/or impurities. Although modified by ion irradiation, the optical properties of the ZnO crystals, except for the UV emission lifetimes, recover hours after without any sample treatment and only at room temperature. Compared with the H-ion-irradiated sample, the D-ion-irradiated crystal has a slower recovery which may be related to the ions' masses, energy losses, and absolute diffusivities. Our results nevertheless show that bulk ZnO single crystals exhibit resistance to and recovery from H-ion and D-ion irradiation and can therefore be used as scintillator materials for radiation detectors inside future fusion reactors.