White-light long persistent and photo-stimulated luminescence in CaSnSiO5:Dy3+

•White-light long persistent luminescence in CSSO:Dy3+ was observed.•White-light photo-stimulated luminescence in CSSO:Dy3+ was observed.•A model for energy storing and releasing through the IR irradiation was presented.

CaSnSiO5:Dy3+ exhibits white-light long persistent and photo-stimulated luminescence properties, originated from both the emission band of the host extending from UV to blue and the characteristic transitions 4F9/2 → 6HJ of Dy3+. Shallow and deep traps are evidenced by the thermoluminescence (TL) and positron annihilation (PA) techniques. TL glow curve of the material with low Dy3+ content exhibits a single band located around 300 K, which is quite favorable for room temperature persistent luminescence. The low-temperature TL band is suppressed with increasing Dy3+ concentration, while the intensity of the high temperature TL band (520 K) increases and finally becomes the dominant band. It is worth noting that the presence of deep traps being able to immobilize the carriers permanently at room temperature. Under 980 nm-light stimulation, a small part of the stored energy could be released and contribute to the observation of the weak white-light emitting. PA results demonstrate that it is attributed to the creation of the cluster defects 2DyCa•·VCa″ with increasing Dy3+ concentration, which make it more difficult for trapped carriers to be released at room temperature.

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