Tailorable Multicolor Up‐conversion Emissions in Tm³⁺/Ho³⁺/Yb³⁺ Co‐Doped LiLa(MoO₄)₂

Abstract

Using a modified sol–gel method, LiLa(MoO4)2: Tm3+/Ho3+/Yb3+ phosphors with tailorable up‐conversion (UC) emission colors were prepared. Under the excitation of a 980 nm laser diode, up‐conversion red and green emissions in Ho3+/Yb3+ co‐doped and blue emission in Tm3+/Yb3+ co‐doped LiLa(MoO4)2 were observed, respectively. The intensities of the RGB (red, green, and blue) emissions could be controlled by varying concentrations of Tm3+ or Ho3+, and the optimal composition was also determined. In Tm3+/Ho3+/Yb3+ co‐doped LiLa(MoO4)2, the UC emission colors could be tuned from blue through white to yellow by adjusting the concentrations of Tm3+ or Ho3+. The UC excitation mechanisms were also investigated based on the power dependence of UC luminescence intensity.

Synthesis and Enhanced Visible‐Light Photocatalytic Activity of Tm3+/Yb3+ Co–Doped Bi3.64Mo0.36O6.55

“…Besides, some Tm 3+ ions were much more likely to relax non‐radiatively to 3 H 4 level. As a consequence, a strong NIR emission at 794 nm happened due to the 3 H 4 → 3 H 6 ,. Because of the upconversion, there would be much more energy reached the surface of the host material Bi 3.64 Mo 0.36 O 6.55.…”

Aqueous sol–gel synthesis, thermoanalytical, structural and vibrational studies of lithium aluminium molybdate (LiAlMo2O8)

“…Therefore, the elimination of the starting organometallic compounds from the synthesis procedure creates a novel solution-based synthesis approach, which expands the preparation possibilities for different multicomponent metal oxides and gives a strong additional novelty to this study. Furthermore, the introduction of aqueous media in the mixing stage of individual components at the molecular level [11] significantly decreases the cost of this process and increases its environmental friendliness [12][13][14][15]. In this work, we propose an aqueous tartaric acid-assisted sol-gel synthesis technique for the preparation of lithium aluminium molybdate for LiAlMo 2 O 8 ceramic.…”

NIR-to-NIR and NIR-to-blue light upconversion in stoichiometric NaYb(MO4)2(M = Mo, W)

“…5 Much of this research effort has focused on understanding composition-structure-luminescence relationships in metalates of formula ARE 1−x RE′ x (MO 4 ) 2 , where RE is an optically inert ion (e.g., Y 3+ , La 3+ , Gd 3+ ) and RE′ is an optically active rare-earth ion or pair of ions (e.g., Eu 3+ , Yb 3+ -Er 3+ , Yb 3+ -Tm 3+ ); the latter are typically incorporated in the host at concentrations below 20 mol%. 6,7 Investigation of the crystallochemical basis of energy-transfer processes in hosts featuring near unity concentrations of the optically active ions has comparatively languished. Bridging this fundamental knowledge gap is critical to enable the ratio-nal design and screening of metalates whose full potential as photoluminescent materials is yet to be realized.…”