Properties of optically and thermally stimulated luminescence of novel storage phosphor materials: Doped and undoped CsCaCl₃ ceramics

We report the properties of CsCaCl₃, storage phosphors doped with Eu, Ce, or Cu. Both doped and undoped CsCaCl₃ samples were synthesized as ceramics. For undoped CsCaCl₃, thermally stimulated luminescence (TSL) spectrum showed a broad band around 360390 nm, and optically stimulated luminescence (OSL) spectrum exhibited the same band with a shoulder near 320 nm. These bands were attributed to different kinds of defects or impurities. The OSL and TSL spectra of Eu-doped CsCaCl₃ showed a band around 440 nm arising from the 5d4f transition of Eu²⁺. The Ce-doped CsCaCl₃ showed the OSL and TSL bands originating from the 5d4f transition of Ce³⁺. An intense band at 345 nm appeared in the OSL spectrum of Cu-doped CsCaCl₃ due to Cu⁺, and an additional peak at 430 nm was ascribed to Cu⁺ ion perturbed by OH¹ ion. On the other hand, the TSL spectrum of Cu-doped CsCaCl₃ had a peak around 470 nm and it was assigned to Cu²⁺. The TSL glow curves of the undoped, Eu-doped, Ce-doped, and Cu-doped CsCaCl₃ were different from each other. This suggested that the dopant ions influenced the trapping process of electronhole pairs, which were formed upon irradiation.