新型Sr_3Y(PO_4)_3∶Ce^(3+),Tb^(3+)绿光荧光粉的制备与发光机理的研究  

Study on Synthesis and Luminescence Mechanism of Novel Green Sr_3Y(PO_4)_3∶Ce^(3+),Tb^(3+) Phosphors

作　　者：董国帅[1] 刘海波[1] 罗莉[1] 王银海[1] 

机构地区：[1]广东工业大学物理与光电工程学院,广东广州510006

出　　处：《光谱学与光谱分析》2015年第8期2189-2193,共5页Spectroscopy and Spectral Analysis

基　　金：国家自然科学基金项目(21271048)资助

摘　　要：采用传统的高温固相法合成了一种新型的绿色荧光粉Sr3Y(PO4)3∶Ce3+,Tb3+,利用X射线衍射(XRD)和荧光光谱(PL)对该材料的晶体结构和光学性能进行表征。结果分析表明,制得样品的XRD图谱不含Sr3Y(PO4)3以外的杂峰,稀土掺杂并未改变基质的晶体结构,得到的样品为纯相的磷酸钇锶。从本文实验中明显观察到Sr3Y(PO4)3∶Tb3+的激发光谱和Ce3+的发射光谱在320~390nm有重叠,表明在Sr3Y(PO4)3基质中可存在从Ce3+到Tb3+的能量传递。在紫外光(315nm)激发下该荧光粉发射出了Ce3+的蓝光(320~420nm)和Tb3+的黄绿光(480~500nm)和(530~560nm),当Ce3+的浓度为7%,Tb3+的浓度由1%增大到50%时,通过Ce3+的4f→5d电子跃迁将能量传递到Tb3+,然后发生5 D4→7 Fj电子跃迁,该荧光粉发射光谱可由蓝光逐渐调节为黄绿光。本文绘制了Ce3+,Tb3+的能级和Sr3Y(PO4)3∶Ce3+,Tb3+荧光粉中的能量转移过程示意图,并详细阐述了由Ce3+到Tb3+的能量传递过程。通过对比Ce3+和Tb3+的发光强度以及由Ce3+到Tb3+能量转移效率的相对变化,可以得出,随着掺入的Tb3+浓度不断增加,Tb3+的发射强度(5 D4→7 Fj)和能量转移效率(Ce3+到Tb3+)也在增大,而Ce3+的发射强度却有了明显的下降。当Tb3+的浓度为50%时能量转移效率可高达80%。通过CIE色度图也可以看出,当Tb3+浓度不断增大,样品的色坐标从图中的蓝色区域移动到绿色区域。所以在紫外光激发下,Ce3+和Tb3+共掺Sr3Y(PO4)3可作为一种绿光荧光粉应用在白光LED或LCD背光源上。A novel green light-emitting phosphor Sr3Y（PO4）3Ce^3＋,Tb^3＋was synthesized by the traditional high temperature solid state reaction method.Luminescence mechanism and crystal structure were investigated by X-Ray Diffraction（XRD）and photoluminescence spectra（PL）.The XRD patterns demonstrate that the samples belong to the single phase of Sr3Y（PO4）3in experimental doping concentrations range.Obviously,the excitation band of Sr3Y（PO4）3∶Tb^3＋and the emission of Sr3Y（PO4）3∶Ce^3＋have a significant spectral overlap in the wavelength range of 330～380nm,which implies the great possibility of an efficient ET from Ce^3＋to Tb^3＋.Under the 315 nm ultraviolet excitation,a blue emission（320～420nm）from Ce^3＋and a yellowishgreen emission（480～500,530～560nm）from Tb^3＋were obtained from Sr3Y（PO4）3∶Ce^3＋,Tb^3＋.When the Ce^3＋concentration was 7%,the emission could be adjusted from blue to green region by tuning the Tb^3＋doping concentrations from 1% to50% through an energy transfer process.This text plot the schematic energy levels of Ce^3＋,and Tb^3＋with electronic transitions and energy transfer processes in Sr3Y（PO4）3∶Ce^3＋,Tb^3＋,which disclose the electron motion processes of Sr3Y（PO4）3 ∶Ce^3＋,Tb^3＋.From the dependence of relative emission intensity of Ce^3＋,Tb^3＋（^5 D4→^7Fj）and ET efficiency from Ce^3＋to Tb^3＋on the concentrations of Tb^3＋,It can be seen that the relative intensity of Tb^3＋and the values ofηETincrease gradually with the increasing of Tb^3＋as well as the relative intensity of Ce^3＋decreases remarkably.The largest energy transfer efficiency reaches as high as 80% when the concentration of Tb^3＋was 50%,demonstrating the efficient energy transfer from Ce^3＋to Tb^3＋.The CIE chromaticity coordinate positions are plotted,as can be seen the emitting color of Ce^3＋and Tb^3＋singly doped Sr3Y（PO4）3∶Ce^3＋,Tb^3＋phosphor are blue and yellowish green,respectively.The emitting color of samples

关 键 词：稀土 磷酸钇锶 能量传递 

分 类 号：O482.3[理学—固体物理]