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 360–390 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 5d–4f transition of Eu2+. The Ce-doped CsCaCl3 showed the OSL and TSL bands originating from the 5d–4f 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 OH− 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 electron–hole pairs, which were formed upon irradiation.