The Preparation And Photoluminescent Properties Of Several Typical Rare-earth Doped Oxide Phosphors

Aiming at the demand for the novel phosphors utilized in illumination and display, by selecting several typical oxysalts as host materials, a phosphate, three silicates and a zirconate activated by Eu2+, Tm3+, Ce3+, Tb3+, Dy3+ ions et al. were synthesized, and their potential possibility as novel UV-LED and PDP phosphors were first explored and discussed in this paper. From the angle of basic theory and practical value, the results abovementioned would significantly contribute to the exploration of the photoluminescent properties for the new kinds of oxysalt phosphors and the promotion of the application in illumination and display fields.First, merrillite structuredβ-NaCaPO4 host was doped by blue-emitting ion Tm3+. The UV-VUV photoluminescent properties ofβ-NaCaPO4:Tm3+ was first investigated by UV-Vis absorption spectra, excitation and emission spectra in UV and VUV region, and all the peaks in the curves were attributed. The results indicated thatβ-NaCaPO4:Tm3+ could generate blue light with good color purity by UV and VUV excitation, the thermal stability of which was evidently better than the commercial blue phosphor. The phosphor could be a new potential blue phosphor for PDP.Second, single phase of Ba13Al22Si10O66 with the derivative of BaAl2O6 structure was successfully prepared by adjusting and controlling the ratio of Al/Si in raw materials, and the photoluminescent properties of the host activated by Eu2+, Ce3+ and Tb3+ in UV-VUV region was explored. White-emitting phosphor Ba13Al22Si10O66:Eu2+ with the characteristic luminescence of Eu2+ was first obtained without reducing atmosphere and was proved to have bluish white long afterglow. This phosphor could be adopted by white LED and was a new potential long afterglow phosphor. Furthermore, Ba13Al22Si10O66: Ce3+ and Ba13Al22Si10O66: Tb3+ could generated intense luminescence by UV excitation. However, the three phosphors Ba13Al22Si10O66: Eu2+, Ce3+, Tb3+ hardly emitted light in VUV region, which were not proper to serve as PDP phosphor.Third, several representative rare-earth ions (Eu2+, Tm3+, Ce3+, Dy3+) were introduced in the silicates host Li4SrCa(SiO4)2, and their photoluminescent properties were first discussed in UV-VUV region. Li4SrCa(SiO4)2: Eu2+ could generate bluish purple emission by UV excitation, which was a potential blue-emitting phosphor utilized by white LED. Li4SrCa(Si04)2:Tm3+ emitted the characteristic emission of Tm3+ by UV and VUV irradiation, which was blue light with good color purity. The strongest VUV excitation peak of the sample matched well with the wavelength that the Xe gas discharged; hence it could be suitable serve as PDP phosphors. By UV and VUV excitation, Li4SrCa(SiO4)2:Ce3+ could produce 5d-4f characteristic emission of Ce3+ by both UV and VUV excitation, however, apropos to the color purity, the sample under UV excitation was proper to be adopted by white LED. The luminescence of Li4SrCa(SiO4)2: Dy3+ generated the characteristic f-f emission of Dy3+ by UV and VUV excitation, which was yellowish and needed to be improved.Fourth, the UV-VUV photoluminescent properties of rare-earth focal silicateβ-Y2Si2O7 doped with Ce3+, Tb3+ or Ce3++Tb3+ were studied, and the energy transfer process of the two ions in VUV region were first explored. Hence the potential possibility for it to serve as PDP phosphor was valued.Fifth, double-perovskite-structured CaZrO3 was doped with Dy3+, Tm3+ and Dy3++Tm3+. The energy transfer process of Dy3+ and Tm3+ in co-doped samples was investigated, and the co-doped samples were potentially utilized in white LED.