Cr3+ doped Ca14Zn6Ga10O35: A near-infrared long persistent luminescence phosphor

The near-infrared persistent phosphors have attracted increasing attention due to the potential application in in vivo imaging. Exploring new materials to realize efficient near-infrared persistent luminescence is a goal of general concern. Ca14Zn6Ga10O35:Cr3+phosphor gives a near-infrared long persistent luminescence over 3 h with the 650-750 nm emission range after the short UV-irradiation. The afterglow behaviors such as the persistent luminescence, the trap depth distribution, the trap types and the underlying mechanism for persistent luminescence, were comprehensively surveyed by means of thermoluminescence methods and electron spin resonance spectra. In addition, Al dopant was introduced to redeploy the trap distribution in Ca14Zn6Ga10O35:Cr3+ phosphor. Compared with the well-known phosphor ZnGa2O4:Cr3+, Ca14Zn6Ga10O35:Cr3+ is proved to be a new NIR persistent phosphor potentially suitable for in vivo imaging due to its 650-750 nm emission range.