X‐ray–induced multicolor long afterglow and photostimulated luminescence from Pr ³⁺ ‐doped Sr ₃ (PO ₄ ) ₂

Abstract In this paper, X‐ray–induced multicolor long afterglow and photostimulated luminescence from Sr 3 (PO 4 ) 2 : Pr 3+ was reported. The Rietveld refinement results have confirmed the as‐prepared sample was pure Sr 3 (PO 4 ) 2 phase with hexagonal crystal system. And Sr 3 (PO 4 ) 2 : Pr 3+ showed an excellent X‐ray–induced long afterglow luminescent performance. Under the excitation of X‐ray, the sample showed multicolor long afterglow luminescence from UVC to red region located at 268, 359, 466, 548, 604.3 and 685 nm, which can be ascribed to 4 f 5 d ‐ 3 H 4 , 4 f 5 d ‐ 1 D 2 , 4 f 5 d ‐ 3 P 0 , 3 P 0 → 3 H 5 and 1 D 2 → 3 H 4 , respectively. And the strongest afterglow emission intensity appeared at 468 nm. Furthermore, only 30 s X‐ray irradiation can induce 12 h afterglow emission, which afterglow emission intensity of 468 nm still reached 3.71 × 10 4 cps and was about 37.1 times stronger than the background intensity. In particular, the relation between 268 nm afterglow emission intensity and 468 nm afterglow emission intensity showed good linearity. And the UVC afterglow emission can be easily “observed” via the visible afterglow light. Furthermore, Sr 3 (PO 4 ) 2 : Pr 3+ possessed an excellent photostimulated luminescence (PSL) under the excitation of 980 nm NIR laser and the PSL intensity of the 12 circle still arrived at 1.26 × 10 5 cps, which was about 37.1 times stronger than the afterglow emission intensity after 5 h decay. All these results showed that the as‐prepared Sr 3 (PO 4 ) 2 : Pr 3+ phosphor was an excellent X‐ray–induced long afterglow luminescence phosphor, which possessed large potential applications in the medical field.