The luminescence of CaYBO4:RE3+ (REb, Ce) in VUV–visible region

Abstract: Phosphors CaYBO4:RE3+ (RE=Eu, Gd, Tb, Ce) were synthesized with the method of solid-state reaction at high temperature, and their vacuum ultraviolet (VUV)–visible luminescent properties in VUV–visible region were studied at 20K. In CaYBO4, it is confirmed that there are two types of lattice sites that can be substituted by rare-earth ions. The host excitation and emission peaks of undoped CaYBO4 are very weak, which locate at about 175 and 350–360nm, respectively. The existence of Gd3+ can efficiently enhance the utilization of host absorption energy and result in a strong emission line at 314nm. In CaYBO4, Eu3+ has typical red emission with the strongest peak at 610nm; Tb3+ shows characteristic green emission, of which the maximum emission peak is located at 542nm. The charge transfer band of CaYBO4:Eu3+ was observed at 228nm; the co-doping of Gd3+ and Eu3+ can obviously sensitize the red emission of Eu3+. The fluorescent spectra of CaYBO4:Ce3+ is very weak due to photoionization; the co-addition of Ce3+–Tb3+ can obviously quench the luminescence of Tb3+. [Copyright &y& Elsevier]