一种上转换白光荧光粉的制备与发光性能研究

Preparation and Up-Conversion Luminescence Properties of White AlF_3-YbF_3:Er^(3+)/Tm^(3+) Phosphors

采用高温固相法制备了上转换白光荧光粉AlF3-YbF3:Er3+/Tm3+。通过XRD物相分析可知:上转换白光荧光粉AlF3-YbF3:Er3+/Tm3+是由三方AlF3相和正交YbF3相组成;利用发射光谱研究了该荧光粉的上转换发光性能,并且分析了当固定Er3+离子掺杂浓度时,Tm3+离子掺杂浓度对上转换白光荧光粉AlF3-YbF3:Er3+/Tm3+色度的影响,进而提出其上转换能量传递机制。结果表明:在980 nm激光激发下,波长为410 nm的紫光峰、550 nm的绿光峰和660 nm的红光峰分别对应于荧光粉中Er3+离子的2H9/2→4I15/2,4S3/2→4I15/2和4F9/2→4I15/2能级的跃迁,而波长为360 nm的紫外光峰、450 nm的蓝光峰、700 nm的红光峰,分别对应于荧光粉中Tm3+离子的1D2→3H6,1G4→3H6和1G4→3F4能级的跃迁,Er3+离子发出的光与Tm3+离子发出的光最终混合成色坐标为x=0.32,y=0.36的白光。此外,通过980 nm半导体激光器和EPM 2000 Dual-channel Joulemeter/Power meter测得该荧光粉最大上转换效率为6.90%。

AlF3-YbF3：Er^3＋ was prepared by high temperature solid state reaction.The crystal structures of the phosphors were characterized by means of X-ray diffraction（XRD）.It could be seen from X-ray diffraction that the white up-conversion phosphor AlF3-YbF3：Er^3＋/Tm^3＋ contained rhombohedra AlF3 phase and orthorhombic YbF3 phase.The conversion energy transfer mechanism of the phosphors and the concentration effect of Tm^3＋ on color coordinates of phosphors were studied through the emission spectra of the phosphor.The results showed that under 980 nm laser excitation,the violet peak（410 nm）,green peaks（550 nm） and red peaks（660 nm） were due to 2H9/2→^4I15/2,4S3/2→^4I15/2 and ^4F9/2→^4I15/2 energy level transition of the Er^3＋ ions,and the UV peaks（360 nm）,blue peaks（450 nm） and red peaks（700 nm） were corresponding to 1D2→3H6,1G4→3H6 and 1G4→3F4 energy levels transition of Tm^3＋ ions.Finally,the blue peak,green peaks and red peaks were mixed into the white light（color coordinates： x=0.32,y=0.36）.In addition,we measured the maximum upconversion efficiency 6.90% of phosphors by 980 nm semiconductor laser device and EPM 2000.