Tunable Luminescence and Ce³⁺ → Tb³⁺ → Eu³⁺ Energy Transfer of Broadband-Excited and Narrow Line Red Emitting Y₂SiO₅:Ce³⁺, Tb³⁺, Eu³⁺ Phosphor

Abstract

The Ce3+ → Tb3+ → Eu3+ energy-transfer process enables Eu3+5D0 → 7F J line emission to be sensitized by the allowed Ce3+ 4f1 → 5d1 absorption transition in near-ultraviolet (NUV) and violet spectral regions. This energy-transfer strategy is applied in Y2SiO5:Ce3+, Tb3+, Eu3+ powders, leading to line-emitting red phosphors that can be excited by short-wavelength InGaN LEDs. The blue, green, and red colors can be tuned by the ratio of Ce3+/Tb3+/Eu3+. Furthermore, the energy-transfer efficiencies and corresponding mechanisms are discussed in detail, and the thermal stability is evaluated. The results suggest that the optimal composition phosphor Y2SiO5: 0.01Ce3+, 0.50Tb3+, 0.01Eu3+, which exhibits an intense Eu3+ red 4f–4f sharp emission with a strong 4f–5d absorption band of Ce3+ at the NUV region, could serve as a potential broadband-excited and narrow line red phosphor for NUV LEDs.

Luminescent properties and energy transfer studies of color-tunable LuBO 3 : Ce 3+ /Tb 3+ /Eu 3+ phosphors

“…Yen, energy transfer rate of f-d: f-f ions pair is approximately two orders of magnitude higher than that of f-f: f-f ions pair [36]. In our previous study of Ce 3+ →Tb 3+ →Eu 3+ energy transfer in Y 2 SiO 5 system, it is found that Tb 3+ →Eu 3+ energy transfer mechanism is the exchange interaction, which requires close sensitizer-activator distance (< 10 Å) for efficient energy transfer [18]. Due to relative low Tb 3+ →Eu 3+ energy transfer rate, it is reasonable that the Tb 3+ content in Ce 3+ →Tb 3+ → Eu 3+ energy transfer should be high (> 40 %) to maximize Tb 3+ →Eu 3+ energy transfer rate, shorten the Tb 3+ -Eu 3+ distance and alleviate MMCT process.…”

“…A. Setlur, Tb 3+ could be served as a bridge to alleviate the MMCT effect between Ce 3+ and Eu 3+ [15]. Thus, Ce 3+ →Tb 3+ →Eu 3+ is a promising strategy to enhance the red emission of Eu 3+ 4f-4f red emission, which has been verified in Na 2 Y 2 B 2 O 7 : Ce 3+ , Tb 3+ , Eu 3+ [16], GdBO 3 : Ce 3+ , Tb 3+ , Eu 3+ [17] and Y 2 SiO 5 : Ce 3+ , Tb 3+ , Eu 3+ [18]. It is found that a high Tb 3+ content is required in Ce 3+ →Tb 3+ →Eu 3+ process for sensitizing Eu 3+ red emission, such as YBO 3 :…”

Enhancing the luminescent properites of Zn2P2O7: Ce3+, Dy3+ via efficient energy transfer

“…Its ground state configuration is 4f 1 , and its first excited state configuration is 5d 1 . As a sensitizer, it was proved that the Ce 3+ [15][16][17][18][19][20].…”

White light emission and effect of annealing on the Ho 3+ –Yb 3+ codoped BaCa 2 Al 8 O 15 phosphor

“…Generally, Er 3+ , Ho 3+ , Tb 3+ and Ce 3+ ions are used for green and red light emissions and sometimes Eu 3+ is also used for red light emission [4][5][6][7] . Tm 3+ is profoundly used for blue light emission and hence a wide combination of tri-doped rare earth ions have been reported using these rare earth ions with the dopingof Yb 3+ as sensitizer in different host materials 1,[8][9][10] .…”