NaYF4∶Eu3+, Tm3+, Yb3+材料中Stokes和反Stokes发光研究

合成了Eu3+， Tm3+和Yb3+掺杂的NaYF4材料。360 nm光激发呈蓝色发光， 峰值位于452 nm， 对应Tm3+的1D2→3F4跃迁； 395 nm光激发呈橙色发光， 峰值位于591 nm， 对应Eu3+的5D0→7F1跃迁； 409 nm光激发呈红色发光， 峰值位于613 nm， 对应Eu3+的5D0→7F2跃迁； 980 nm光激发呈蓝色和红色发光， 发光峰位于474和646 nm。蓝光来源Tm3+的1G4 →3H6跃迁， 红光来源Tm3+的1G4→3F4跃迁。在双对数曲线中， 蓝光474 nm和红光646 nm的斜率分别为2.1和2.4， 在980 nm光激发下， 蓝光和红光发射都是双光子过程。还研究了材料的吸收光谱， 并利用X射线衍射， 扫描电镜测试了材料的物相结构和微观形貌。结果表明： NaYF4∶Eu3+, Tm3+, Yb3+材料具有较规则的六方相结构， 结晶良好。

Stokes and Anti-Stokes Luminescence Research of NaYF4∶Eu3+, Tm3+, Yb3+

The sample of NaYF4∶Eu,Tm,Yb was synthesized by coprecipitation method. The emission of NaYF4∶Eu,Tm,Yb excited by 360 nm is blue light with the peak at 452 nm from the transition of 1D2→3F4 of Tm3+. After being excited by 395 nm, NaYF4∶Eu,Tm,Yb emits orange light with the peak at 591 nm originating from the transition of 5D0→7F1 of Eu3+. When excited by 409 nm, NaYF4∶Eu,Tm,Yb emits red light with the peak at 613 nm from the transition of 5D0→7F2 of Eu3+. The color of upconversion luminescence of NaYF4∶Eu,Tm,Yb excited by 980 nm was blue and red. The upconversion spectrum exhibits distinct emission peaks at 459, 478 and 641 nm. The blue light comes from the transition of 1G4→3H6 and 1D2→3F4 of Tm3+. The absorption spectrum was also researched. The red light results from the transition of 1G4→3F4 of Tm3+. The slope of the emission of 474 and 646 nm is 2.1 and 2.4 respectively. The emission of 478 and 641 nm is all due to three photon process. The structural properties of sample were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The results show that NaYF4∶Tm3+,Yb3+ prepared by coprecipitation method exhibits a hexagonal crystal.