Abstract: Trivalent Dy3+ and trivalent Eu3+ ions co-doped NaY(WO4)2 upconversion phosphors were synthesized via traditional hydrothermal process. The effects of drying routes on the crystal structure, morphology, particle size and upconversion luminescence properties were investigated, and characterized by XRD, SEM, and photoluminescence spectrum (PL). The results showed that all the synthesized samples had the tetragonal scheelite structure with the space group I41/a, and the doping Dy3+ and Eu3+ ions did not evoke the changes of the host lattice parameters. In addition, the shape and size of products could be changed simply and effectively by different drying methods. The particle sizes of the phosphors drying by normal, spray, freeze and vacuum methods were 817.91, 486.04, 388.74 and 349.82 nm, respectively. It should be noted that the excellent dispersion of the particles were obtained by vacuum drying method. Under near infrared light excitation at 793 nm, the sample obtained by freeze drying had the better upconversion luminescence property than samples synthesized by normal drying, spray drying and vacuum drying. The possible reason for the above phenomenon were spread uniform, reunite decrease and surface defect layer decrease of powder particles during the freeze drying process. The NaY(WO4)2:Dy3+, Eu3+ phosphors exhibited yellow emission band at 576 nm corresponding to the 4F9/2→6H13/2 transition of Dy3+ ions, orange emitting lights (595 nm) were from the transition of 5D0→7F1 of Eu3+ ions, and red emitting lights at 616 and 655 nm, which were assigned to the energy level transition of 5D0→7F2 and 5D0→7F3 of Eu3+ ions, respectively. Moreover, the ideal red chromaticity was exhibited by the CIE color coordinates of NaY(WO4)2:Dy3+, Eu3+ phosphors. In view of this, the NaY(WO4)2:Dy3+, Eu3+ phosphors might have potential application in photoelectric device areas, such as light emitting diodes and color display systems.

Key words: hydrothermal method, drying routes

摘要： 采用水热法合成了Dy3+和Eu3+共掺杂的NaY(WO4)2上转换荧光粉，用XRD, SEM和荧光光谱(PL)等方法对不同干燥方式所得样品的晶体结构、微观形貌、晶粒尺寸及上转换发光性能进行了分析。结果表明，合成样品均为四方白钨矿结构的NaY(WO4)2，空间群为I41/a，掺入Dy3+和Eu3+未改变基质晶格；常规干燥、喷雾干燥、冷冻干燥及真空干燥后荧光粉的尺寸分别为817.91, 486.04, 388.74和349.82 nm，真空干燥的样品分散性最好。在793 nm近红外光激发下，冷冻干燥样品的上转换发光性能最佳，与干燥过程中粉体团聚程度减弱及表面层缺陷减少有关。576 nm处的黄光发射峰来自Dy3+的4F9/2→6H13/2跃迁，595 nm处的橙光、616和655 nm处的红光发射峰分别归属于Eu3+的5D0→7F1, 5D0→7F2和5D0→7F3跃迁。荧光粉的CIE色坐标均位于红光区，表现出良好的红光发射特性，在发光二极管和彩色显示等光电领域具有潜在应用价值。

关键词: 水热法, 干燥方式