Synthesis and optical properties of green emitting garnet phosphors for phosphor-converted light emitting diodes
Synthesis and optical properties of green emitting garnet phosphors for phosphor-converted light emitting diodes
复制标题
DOI：
10.1016/j.optmat.2012.01.034
复制
发表时间：
2012-05
影响因子：
3.9
通讯作者：
A. Katelnikovas;J. Plewa;D. Dutczak;S. Möller;D. Enseling;H. Winkler;A. Kareiva;T. Jüstel
中科院分区：
文献类型：
--
作者：
A. Katelnikovas;J. Plewa;D. Dutczak;S. Möller;D. Enseling;H. Winkler;A. Kareiva;T. Jüstel
采用溶胶-凝胶燃烧法制备了一系列Ce3+掺杂的CaLu2Al4SiO12石榴石荧光粉。用粉末X射线衍射(XRD)、热猝灭(TQ)、荧光寿命和光致发光(PL)等方法对样品进行了表征。此外，还测定并讨论了发光效率(LE)、CIE1931色点和量子效率(QE)。X射线衍射谱证实，所有样品都存在单相石榴石，与Ce3+浓度无关，至少高达3mo1%。荧光粉在460-720 nm范围内表现出宽带发射。与Lu3Al5O12：Ce3+相比，发射带的最大值发生了蓝移，并且随着Ce3+浓度的增加，发射峰从520 nm移至542 nm。Ce3+掺杂0.25%和0.5%的样品获得了80%~86%的高量子效率，但当Ce3+的掺杂量较高时，样品的光致发光量子效率显著降低，即浓度猝灭。
A series of Ce3+doped CaLu2Al4SiO12garnet phosphors was prepared by a sol–gel combustion technique. All samples were characterized by powder X-ray diffraction (XRD), thermal quenching (TQ), fluorescence lifetime and photoluminescence (PL) measurements. Moreover, luminous efficacies (LE), CIE 1931 color points and quantum efficiencies (QE) were determined and discussed. XRD patterns confirmed the presence of single phase garnet for all samples independent of Ce3+concentration at least up to 3mol%. Phosphors showed a broad band emission in the range 460–720 nm. The emission band maximum is blue-shifted in comparison to Lu3Al5O12:Ce3+and shifts from 520 to 542 nm by increasing the Ce3+concentration. High quantum efficiencies of 80 to 86% were obtained for those samples doped with 0.25% and 0.5% of Ce3+, however, a higher Ce3+doping levels resulted in concentration quenching, i.e. in a substantial decrease of the photoluminescence quantum efficiency.