Synthesis of New RE3+ Doped Li1+xTa1−xTixO3 (RE: Eu, Sm, Er, Tm, and Dy) Phosphors with Various Emission Colors

Abstract

New phosphors with various emission colors for RE3+ doped Li1+xTa1−xTixO3 (LTT) (RE: Eu, Sm, Er, Tm, and Dy) were synthesized by electric furnace at 1423 K for 15 h. The microstructure of the host material and the photoluminescence (PL) property were determined and compared to those of RE3+ doped Li1+xNb1−xTixO3 (LNT). In the LTT phosphor, the highest PL intensity was achieved for the mixture composition Li1.11Ta0.89Ti0.11O3 with a LiTaO3 structure, although it has an M-phase superstructure. In the LTT host material, the effective activators were Eu3+ and Sm3+ ions, in contrast to the LNT host material. Here, we discuss the relationship between PL property and the host material’s structure.

Syntheses and Luminescence Enhancement of Li1+x(Ta1-zNbz)1-xTixO3:RE3+ (RE=Eu, Er, Tm or Dy) Phosphors

“…Optimal compositions and PL properties of LTNT: RE 3+ phosphors In our previous paper, we compared the emission spectra between the two-types of phosphors, RE 3+ -doped Li 1.11 Nb 0.89 Ti 0.11 O 3 (LNT with x=0.11 and y=0) and RE 3+ -doped Li 1.11 Ta 0.89 Ti 0.11 O 3 (LTT with x=0.11 and y=0) as shown in Figure 1 [13] . The resulting materials showed various emission colors, ranging from red for Li Figure 2 shows the relationship between PL intensity and the z value of L 1.11 (Ta 1-z Nb z ) 0.89 Ti 0.11 :RE 3+ (RE 2 O 3 : 2.5 wt%).…”

“…Yellow emission peaks at around 581 nm ( 4 F 9/2 -6 H 13/2 ) were observed for the Li 1.14 (Ta 0.6 Nb 0.4 ) 0.86 Ti 0.14 O 3 :Dy 3+ upon excitation at 356 nm ( 6 H 15/2 -4 M 15/2 ). The PL behavior of the RE 3+ -doped phosphors was not affected by the host material's structure due to the 4f-4f transitions [13,19] .…”

“…For the application of LNT as a phosphor host material, rare earth (RE 3+ =Eu, Er, Tm, or Dy) doped LNT solid solutions have been prepared by heating in air using a conventional electric furnace and/or millimeter-wave furnace [10][11][12] . The RE 3+ -doped LTT phosphors were also successfully synthesized, and their photoluminescence (PL) properties were compared to those of LNT:RE 3+ [13] . Furthermore, we previously reported on a new red-emitting phosphor in the Li 2 O-Nb 2 O 5 -Ta 2 O 5 -TiO 2 system, in which we used the quaternary Li 1+x (Ta 1−z Nb z ) 1−x Ti x O 3 (LTNT, 0 ≤ x ≤0.25, 0 ≤ z ≤ 1.0) solid solution as the host material [14] .…”

Temperature-Dependent and Threshold Behavior of Sm3+ Ions on Fluorescence Properties of Lithium Niobate Single Crystals

“…The trivalent samarium ion (Sm 3+ ), which has a complex energy level structure, exhibits emission in the visible region, and is known for its rich orange emission at 610 nm and red emission 651 nm, both of which originate from the 4 G 5/2 state; such an emission is interesting for many photonic applications. For example, the reddish-orange emission band in the visible region, corresponding to the emission spectra of the 4 G 5/2 → 6 H 7/2 and 4 G 5/2 → 6 H 9/2 transitions, is desirable for uses in high-density optical storage, color displays, medical diagnostics, fluorescent display devices, and sensors [2,3,10,11]. More specifically, Sm 3+ -containing hosts have been offered as infrared counters, as an activated solid, and as a means to increase the photovoltaic solar cell conversion efficiency via down-conversion of the solar spectrum [12,13].…”

Crystal structures and enhancement of photoluminescence intensities by effective doping for lithium tantalate phosphors

“…Recently, Li(Ta 1−x Ti x )O 3−x/2 crystals (0 ≤ x ≤ 0.25), when they are activated with rare-earth ions ( = Sm 3+ , Eu 3+ , Er 3+ , Dy 3+ , and/or Tm 3+ ), have been found to demonstrate the highly efficient emission with various colors upon near ultraviolet (UV) excitation (Nakano et al, 2012(Nakano et al, , 2013. Nakano et al (2012) have investigated the photoluminescence (PL) properties of the Eu 3+ -doped Li(Ta 1−x Ti x )O 3−x/2 phosphors and found that their PL intensities have been dependent on the x-value.…”