Dual-mode modulation of luminescence chromaticity in AgLa(MoO4)2:Yb3+,Ho3+ up-conversion phosphors
Dual-mode modulation of luminescence chromaticity in AgLa(MoO4)2:Yb3+,Ho3+ up-conversion phosphors
复制标题
AgLa(MoO4)(2):Yb3 ,Ho3 上转换荧光粉发光色度的双模调制
DOI：
10.1039/c5tc04193g
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发表时间：
2016-01-01
影响因子：
6.4
通讯作者：
Zhao, Puju
中科院分区：
文献类型：
--
作者：
Li, Ting;Guo, Chongfeng;Zhao, Puju
采用溶胶-凝胶法合成了一系列 Yb3+/Ho3+ 共掺杂和 Yb3+/Ho3+/Ce3+ 三掺杂 AgLa(MoO4)(2) 荧光粉，具有绿光 (542 nm) 和红光 (660 nm) 双色上转换 (UC) 发射，980 nm 近红外 (NIR) 激发。通过将红外激光的脉冲宽度从0.2 ms调整到10 ms并通过两种方法引入Ce3+来调节Yb3+/Ho3+共掺杂样品的UC发射颜色。随着脉冲宽度的增加，发射颜色从纯绿色变为黄色，红绿发射强度比（R/G）增强，在Ce3+含量高达10 mol%时获得单波段红色发射。通过调节脉冲宽度进行色度调制的机制归因于绿色发射态的填充率比红色发射态的填充率更快，这与两个非辐射弛豫（NR）过程有关。荧光寿命测量表明，Ce3+ 掺杂对 R/G 比的增强源于 Ho3+ 和 Ce3+ 之间的两次交叉弛豫 (CR)。此外，通过 Yb3+/Ho3+ 共掺杂和 Yb3+/Ho3+/Ce3+ 三掺杂 AgLa(MoO4)(2) 中瞬态时间依赖性 Ho3+ 发射强度，详细阐述了从非稳态到稳态的动态 UC 发射。这些结果有助于控制非平衡UCL过程的能量转移以及实现稀土掺杂发光材料的动态色度调制。
A series of Yb3+/Ho3+ co-doped and Yb3+/Ho3+/Ce3+ tri-doped AgLa(MoO4)(2) phosphors with green (542 nm) and red (660 nm) double color up-conversion (UC) emissions with 980 nm near-infrared (NIR) excitation were synthesized by a sol-gel process. The UC emission color of the Yb3+/Ho3+ co-doped sample was tuned by adjusting the pulse width of an infrared laser from 0.2 to 10 ms and the introduction of Ce3+ by two methods. The emission color changed from pure green to yellow with the increase of pulse width, and the ratio of red to green emission (R/G) intensity was enhanced and single band red emission was obtained with a content of Ce3+ up to 10 mol%. The mechanism of chromaticity modulation by adjusting pulse width is attributed to the faster population rate of the green emission states than that of the red one which is related to two non-radiative relaxation (NR) processes. The fluorescence lifetime measurements show that the enhancement of the R/G ratio by Ce3+ doping results from two cross relaxation (CR) between Ho3+ and Ce3+. Furthermore, dynamic UC emissions from non-steady-state to steady-state were elaborated upon through transient time-dependent Ho3+ emission intensity in Yb3+/Ho3+ co-doped and Yb3+/Ho3+/Ce3+ tri-doped AgLa(MoO4)(2). These results are helpful in controlling energy transfer of non-equilibrium UCL processes and realizing dynamic chromaticity modulation in rare earth doped luminescent materials.