Cr3+ activated Zn3Al2Ge3O12: a novel near-infrared long persistent phosphor

The near-infrared (NIR) long persistent phosphors have gained considerable attention owing to the potential applications in in vivo imaging. A novel NIR long-persistent phosphors Zn 3 Al 2 Ge 3 O 12 :Cr 3+ was successfully synthesized by a high temperature solid-state reaction. The luminescent properties and the afterglow behaviors of the Zn 3 Al 2 Ge 3 O 12 :Cr 3+ were investigated in detail. On the basis of thermoluminescence analyses, the mechanism of the persistent afterglow of the phosphors was also discussed briefly. The afterglow duration of this phosphor can last more than 12 h with the 650–750 nm emission range after stoppage of 254 nm ultraviolet light irradiation. Specifically, the persistent luminescence intensity and duration were regulated by changing Cr 3+ doping concentration. All the results indicate that the Cr 3+ activated Zn 3 Al 2 Ge 3 O 12 has promising potential of practical applications.