Microwave Sol-Gel Derived Ho3+/Yb3+ Co-Doped NaCaGd(MoO4)3 Phosphors and their Upconversion Photoluminescence

Abstract

NaCaGd(MoO 4) 3 :Ho 3+ /Yb 3+ ternary molybdates were successfully synthesized by microwave sol-gel method for the first time. Well-crystallized particles formed after heat-treatment at 900°C for 16 h showed a fine and homogeneous morphology with particle sizes of 3-5 μm. Under excitation at 980 nm, the UC intensities of the doped samples exhibited strong yellow emissions based on the combination of strong emission bands at the 520-nm and 630-nm emission bands in the green and red spectral regions, respectively. The strong 520-nm emission band in the green region corresponds to the 5 S 2 / 5 F 4 → 5 I 8 transition of Ho 3+ ions, while the strong 630-nm emission band in the red region appears to be due to the 5 F 5 → 5 I 8 transition of the Ho 3+ ions. The optimal Yb 3+ :Ho 3+ ratio was found at 9:1, as indicated by the composition-dependent quenching effect of Ho 3+ ions. The pump power dependence of the upconversion emission intensity and the Commission Internationale de L'Eclairage chromaticity coordinates of the phosphors were evaluated in detail.

Up- and Downconversion Luminescence in Ho³⁺,Yb³⁺-Co-Doped Y₂O₃ Transparent Ceramics Prepared by Spark Plasma Sintering

“…As shown in Fig. 2(b energy transfer, which can be explained with the same theory [37][38][39]. Consequently, the intensity of green photoluminescence increases with increasing Yb 3+ content as shown in Fig.…”

“…Notably, photoluminescence intensity decreased when going from 2 mol% to 3 mol% Yb 3+ . This is attributed to the enhancement of non-radiative transitions caused by interactions between Yb 3+ ions at high Yb content [38]. Figure 9 shows that, like the upconversion photoluminescence intensity, green and red emission intensities increased with increasing near-infrared excitation power.…”

Твердые растворы CaMoO-=SUB=-4-=/SUB=--NaGd(MoO-=SUB=-4-=/SUB=-)-=SUB=-2-=/SUB=-: моделирование свойств и локальной структуры методом межатомных потенциалов

“…Твердые растворы CaMoO 4 −NaGd(MoO 4 ) 2 (CMO−NGM) экспериментально изучались в работах [10][11][12]. В синтезированные золь-гель методом с последующей прокалкой поликристаллические образцы тройного молибдата NaСаGd(MoO 4 ) 3 вводились ионы Er 3+ и Yb 3+ [11] или Но 3+ и Yb 3+ [12], замещавшие до 50% ионов гадолиния. В этих работах было установлено, что, как номинально чистый NaСаGd(MoO 4 ) 3 , так и замещенные образцы тройного молибдата имели структуру шеелита.…”

CaMoO-=SUB=-4-=/SUB=--NaGd(MoO-=SUB=-4-=/SUB=-)-=SUB=-2-=/SUB=- Solid Solutions: simulation of properties and local structure by the method of interatomic potentials

“…CaMoO 4 −NaGd(MoO 4 ) 2 (CMO−NGM) solid solutions were experimentally investigated in [10][11][12]. In polycrystalline samples of NaCaGd(MoO 4 ) 3 triple molybdate obtained by the sol-gel method and additionally annealed the Er 3+ and Yb 3+ [11] or Ho 3+ and Yb 3+ [12] were introduced, that substituted up to 50% of gadolinium ions. In these studies it was found that both nominally pure NaCaGd(MoO 4 ) 3 and substituted samples of triple molybdate had a structure of scheelite.…”