YVO_4∶Tm^(3+)的真空紫外发光性能(英文)

通过高温固相反应合成YVO4∶xTm(x=0.001,0.003,0.005,0.007,0.01,0.03,0.05)蓝色系列粉末状发光材料。经X射线衍射分析产物为单相,属四方锆英石结构,其结果与JCPDS标准卡(72-0861)相符。检测了材料的真空紫外激发光谱和发射光谱。YVO4∶xTm的真空紫外激发光谱在120~350 nm范围内为连续的带状峰,在155 nm和333 nm附近有明显的峰值。在155 nm激发下,YVO4∶xTm的发射光谱由两部分组成,其中主发射峰在474 nm附近呈一尖锐的线状,来自Tm3+的1G4→3H6跃迁;在650 nm左右有一弱发射峰,来自Tm3+的1G4→3H4跃迁。另外,还有一较弱的带状发射,中心位于540 nm左右,来自样品的VO3-4离子的宽带发射。随着Tm3+摩尔分数x由0.001增加到0.005,Tm3+发射光谱强度逐渐增加到最大值。之后随着x继续增加,发射光谱强度逐渐下降,呈现明显的浓度猝灭现象。通过对YVO4∶xTm的光谱分析及其发光机理进行推导,认为YVO4∶Tm3+在紫外及真空紫外激发下,是一种具有较高发光效率以及色纯度较好的蓝色发光材料。

场发射显示器用蓝色YVO_4∶Tm^(3+)纳米荧光粉的制备及性能研究

采用溶剂热法成功地制备出了YVO4∶Tm3+纳米荧光粉,并用X射线衍射仪(XRD)、透射电子显微镜(TEM)、紫外分析仪、紫外可见(UV-Vis)吸收光谱和光致发光(PL)光谱对YVO4∶Tm3+纳米荧光粉进行测试和表征。实验结果表明,YVO4∶Tm3+纳米荧光粉可发出明亮的蓝光,色纯度和发光强度都很高,而且具有良好的热稳定性。因此,YVO4∶Tm3+纳米荧光粉是一种十分适用于场发射显示器的荧光粉。

Broadband downconversion in YVO_4:Tm^(3+),Yb^(3+) phosphors

An efficient near-infrared （NIR） downconversion （DC） by converting broadband ultraviolet （UV） into NIR was demon- strated in YVO4：Tma＋,yb3＋ phosphors. The phosphors were extensively characterized using various methods such as X-ray diffrac- tion, photoluminescence excitation, photoluminescence spectra and decay lifetime to provide supporting evidence for DC process. Upon UV light varying from 260 to 350 nm or blue light （473 nm） excitation, an intense NIR emission of Yb3＋ corresponding to tran- sition of 2Fs/2/5→2F7/2 peaking at 985 nm was generated. The visible emission, the NIR mission and the decay lifetime of the phosphors of various Yb3＋ concentrations were investigated. Experimental results showed that the energy transfer from vanadate group to Yb3＋ via Tm3＋ was very efficient. Application of the broadband DC YVO4：Tma＋,yb3＋ phosphors might greatly enhance response of sili- con-based solar cells.

掺Tm钒酸钇的光学性能

钒酸钇 (YVO4)晶体有高的激光损伤阈值和高的激光输出斜率效率 ,也有很好的机械性能和化学稳定性 .从测量Tm :YVO4晶体的吸收谱入手 ,考虑该晶体的各向异性效应 ,拟合出Tm3+ 的光学强度参量 ,进一步得到了振子强度f,辐射跃迁速率A和积分发射截面Σ等光学参量 .在 35 0— 2 5 0 0nm范围内 ,YVO4晶体基质的吸收很小 ,而Tm3+在YVO4晶体中发光能力很强 ;特有的是蓝光1 D2 →3F4(约为 45 4nm)跃迁有极大的振子强度 (38× 10 - 6 )和积分发射截面 (33× 10 - 1 8cm) ,有利于实现短波长的激光输出 .