An Investigation on the Luminescence and Ce3+→Eu2+ Energy Transfer in Ca9Y(PO4)7:Ce3+,Eu2+ Phosphor

Abstract

A series of Ce 3+ -and Eu 2+ -coactivated Ca 9 Y(PO 4 ) 7 phosphors were synthesized by high temperature solid-state reactions. The Ca 9 Y(PO 4 ) 7 :Ce 3+ ,Eu 2+ phosphor showed two emission bands under 292 nm excitation: the one observed at 342 nm was attributed to the 4f 0 5d 1 → 4f 1 transition of Ce 3+ ion emission, and the other found at 492 nm was assigned to the 4 f 6 5d 1 → 4f 7 transition of Eu 2+ ions. Through an effective resonance-type energy transfer, the Ca 9 Y(PO 4 ) 7 :Ce 3+ ,Eu 2+ phosphors exhibit a systematically varied hues from ultraviolet to blue-greenish and the relative intensity of ultraviolet and blue-greenish emissions can be tuned by properly tuning the relative dopant composition of Ce 3+ /Eu 2+ . The energy transfer from a sensitizer Ce 3+ to an activator Eu 2+ in Ca 9 Y(PO 4 ) 7 host matrix was studied and demonstrated to be a resonant type via a dipole-dipole mechanism based on the decay lifetime analysis. Furthermore, we have calculated the critical distance for Ce 3+ → Eu 2+ energy transfer to be about 30.7 Å by both concentration quenching and spectral overlap methods.

Influence of Al3+co-doping on the spectral properties of europium doped Ca9Y(PO4)7

“…In the case of the un-co-doped material, the band with a maximum at 488 nm dominates, while in the materials co-doped with Al 3+ the emission intensity of this band decreases with increasing aluminum concentration. The existence of two emission bands suggests that the Eu 2+ ions are incorporated into at least two different sites characterized by In accordance with previous studies 22,23 the typical emission band of Eu 2+ incorporated in Ca 9 Y(PO 4 ) 7 is observed with a maximum at 488 nm. However, other positions of the Eu 2+ band were also observed aer a modication of the phosphor matrix.…”

Synthesis, photoluminescence and Judd–Ofelt analysis of red LiGd5P2O13 : Eu3+ phosphors for white LEDs

“…19 Eqn (3) can thus be represented by the follow equation: Q ¼ 3 stands for energy transfer among the nearest neighbor ions, while Q ¼ 6, 8 and 10 stands for dipole-dipole, dipole-quadrupole, and quadrupole-quadrupole interactions.…”

Photoluminescence properties and energy transfer of Eu3+,Bi3+ co-doped Ca9Y(PO4)7 phosphors

“…Ca 9 Y(PO 4 ) 7 exhibits a rhombohedral phase, which belongs to space group R3c (No.161) (lattice parameters: a=b=10.4442 Å, c=37.324 Å, Z=6, and V=3525.89 Å 3 ). Some of these phosphors present good luminescence performance and have potential applications in wLEDs [9][10][11]. However, we believe that the related reports about Bi 3+ and Eu 3+ co-doped Ca 9 Y(PO 4 ) 7 have not been reported yet.…”