Persistent Photoconductivity in electron-irradiated ZnO bulk single crystals: Evaluation of the metastable conductive state by the dual light illumination

► We examine Persistent Photoconductivity (PPC) in 30 MeV electron-irradiated ZnO. ► PPC studies are carried out under the dual light (blue and infrared) illumination. ► Below 160 K, the remarkable reduction in PPC is observed after infrared illumination. ► This attributes to the release of electrons from the metastable conductive state.