Highly efficient up-conversion green emission in Ho/Yb co-doped yttria-stabilized zirconia single crystals
Highly efficient up-conversion green emission in Ho/Yb co-doped yttria-stabilized zirconia single crystals
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DOI：
10.1016/j.jlumin.2019.01.041
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发表时间：
2019-05-01
影响因子：
3.6
通讯作者：
Deng, Wen
中科院分区：
文献类型：
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作者：
Tan, Xiaojun;Xu, Shoulei;Deng, Wen
在具有有价值的发光性能的材料的开发中，我们已经使用的光学浮区法制备的立方相的氧化钇稳定的氧化锆（YSZ）掺杂有0.75摩尔%的Ho 2 O3和各种浓度的Yb 2 O3的单晶。测定了Yb 3+含量对样品的吸收光谱、光致发光光谱和室温荧光衰减曲线的影响。吸收光谱由几个峰组成，这些峰可以归属于涉及Yb 3+和Ho 3+离子的各种跃迁，以及振子强度参数Omega（t）。（t = 2，4，6）是使用Judd-Ofelt理论确定的，沿着还有跃迁几率，寿命，从0.75mol%Ho2O3和1.5mol%Yb2O3共掺杂的YSZ晶体的吸收和发射光谱的分支比。Omega（2）值近似于14 × 10（-20）cm（2），表明Ho 3+周围的键合比其他几种基质具有更低的对称性和更高的共价性，Omega（4）/Omega（6）比值为1.93，表明该样品是高质量激光输出的良好候选材料。在980 nm激光激发下，0.75 mol%Ho2O3掺杂的YSZ在绿色、红色和近红外（758 nm）波长处的上转换发射光谱显示，Yb 3+掺杂显著增强了YSZ的上转换发射强度，在1.5 mol%Yb2O3时达到最大值。在557 nm处的发射比类似组成的纳米晶体所报道的发射尖锐得多，其中在540 nm处观察到最大强度。下转换荧光光谱显示出1040 nm和1213 nm两个显著的发射峰，荧光衰减曲线表明Yb 3+和Ho 3+之间的能量转移影响了Ho 3+的激发态寿命，其寿命随Yb 2 O3浓度的变化而变化。这些结果表明，这些Yb/Ho共掺杂YSZ晶体具有相当大的激光和发光应用的潜力。
In the development of materials with valuable luminescence properties, we have used the optical floating zone method to prepare single crystals in the cubic phase of yttria-stabilized zirconia (YSZ) doped with 0.75 mol% Ho2O3 and various concentrations of Yb2O3. The influence of Yb3+ contents was determined for absorption and photoluminescence spectra, and fluorescence decay curves at room temperature. The absorption spectra consisted of several peaks that could be assigned to various transitions involving Yb3+ and Ho3+ ions, and oscillator strength parameters Omega(t) (t = 2, 4, 6) were determined using the Judd-Ofelt theory, along with the transition probability, lifetime, and branching ratio from the absorption and emission spectra of the crystal of YSZ co-doped with 0.75 mol% Ho2O3 and 1.5 mol% Yb2O3. The Omega(2) value of similar to 14 x 10(-20) cm(2) indicates that the bonding around Ho3+ involves lower symmetry and higher covalency than in several other hosts, and the value of the ratio Omega(4)/Omega(6) of 1.93 shows that this sample is a good candidate material for high quality laser output. Upconversion emission spectra showed that Yb3+ doping significantly increased the emission intensity of 0.75 mol % Ho2O3 doped YSZ at green (557 nm), red (670 nm) and NIR (758 nm) wavelengths when excited by a 980 nm laser, and reached a maximum for 1.5 mol% Yb2O3. The emission at 557 nm was much sharper than that reported for nanocrystals of similar composition, where the maximum intensity was observed at 540 nm. Down-conversion PL spectra showed two prominent emission peaks at 1040 nm and 1213 nm, and the fluorescence decay curves indicate that energy transfer between Yb3+ and Ho3+ influenced the lifetime of the excited state of Ho3+ which varied with Yb2O3 concentration. Overall these results indicate that these Yb/Ho co-doped YSZ crystals have considerable potential for laser and luminescence applications.