UV Luminescence Property of YPO₄:RE (RE = Ce³⁺, Tb³⁺)

Abstract

Blue-emitting YPO4:Ce3+ and green-emitting YPO4:Tb3+ and YPO4:Ce3+,Tb3+ phosphor particles were synthesized by coprecipitation method. Their structure and micromorphology have been analyzed by X-ray powder diffraction (XRD), FTIR spectra, and scanning electronic microscope (SEM). The transitions of Ce3+ 5d−4f and Tb3+ 5D4−7F J (J = 6−3) were detected, and the photoluminescence intensity of the Tb3+ increased on increasing the concentration of Ce3+. Finally, the energy-transfer process from Ce3+ to Tb3+ was investigated in YPO4:Ce3+,Tb3+ nanoparticles in detail. These nanoparticles can be potentially used as labels for biological molecules.

Dispersible crystalline nanobundles of YPO4 and Ln (Eu, Tb)-doped YPO4: rapid synthesis, optical properties and bio-probe applications

“…6b). The observed emissions lines at 488, 543, 587 and 620 nm correspond to transitions from 5 D 4 energy level to 7 F 6 , 7 F 5, 7 F 4 and 7 F 3 energy levels, respectively (Lai et al 2008;RodriguezLiviano et al 2011). The excitation spectrum obtained for the Tb-doped YPO 4 nanobundles, monitored at the most intense emission of Tb 3?…”

“…6a. A strong luminescence in the orange-red region can be seen, and the groups of emission lines at 592, 619, 650 and 696 nm correspond to emission from the lowest excited 5 D 0 level to the 7 F 1 , 7 F 2 , 7 F 3 and 7 F 4 levels, respectively (Lai et al 2008(Lai et al , 2007Rodriguez-Liviano et al 2011;Yang et al 2009). The excitation spectrum of the as-prepared Eudoped YPO 4 nanobundles (inset in Fig.…”

“…6a) shows a broad and strong absorption band centred at *240 nm corresponding to Eu-O charge transfer transition/band (CTB) which is caused by electron delocalization from the filled 2p shell of O 2-to the partially filled 4f subshell of Eu 3? ion (Lai et al 2008;RodriguezLiviano et al 2011). In addition to the strong charge transfer band, many weak emission lines due to direct excitation of the Eu 3?…”

Preparation of LaPO 4 :Ce 3+ ,Tb 3+ nanophosphors by mixed co-precipitation process and their photoluminescence properties

“…This fact implied an efficient energy transfer (ET) from Ce 3 þ to Tb 3 þ ions. [3,29,30]. The peak centered at 265 nm had the highest excitation intensity.…”

“…In Ce 3 þ and Tb 3 þ co-doped phosphors, Ce 3 þ ion with optically allowed d-f transitions serves as an efficient activator for pumping Tb 3 þ emission. So, UV excitation of Ce 3 þ ion gives rise to intense Tb 3 þ emission by an effective energy transfer from Ce 3 þ to the high excitation levels of Tb 3 þ (4f 8 ), followed by cross relaxation to the 5 D 4 level of Tb 3 þ [3,29,31]. The PL intensity of the 5 D 4 -7 F 5 green emission was plotted as a function of Tb 3 þ doping concentration and is shown in the inset of Fig.…”