Luminescence properties of Sm3+-doped Sr3Sn2O7 phosphor

We report on a luminescent phenomenon in Sm3+-doped Sr3Sn2O7 afterglow phosphor. XRD, photoluminescence, afterglow emission spectra and long-lasting phosphorescence decay curve are used to characterize this phosphor. After irradiation by a 267-nm UV light for 5 min, the Sm3+-doped Sr3Sn2O7 phosphor emits intense reddish-orange emitting afterglow from the 4G5/2 to 6HJ (J = 5/2, 7/2, 9/2) transitions, and its afterglow can be seen with the naked eye in the dark clearly for more than 1 h after removal of the excitation source. Photoluminescence spectra reveal that the reddish-orange light-emitting long-lasting phosphorescence originate from the mixture of Sm3+ characteristic transitions. The afterglow decay curve of the Sm3+-doped Sr3Sn2O7 phosphor contains a fast decay component and another slow decay one. The possible mechanism of this reddish-orange light-emitting LLP phosphor is also discussed based on the experiment results.