Sr_4Al_(14)O_(25)∶RE^(3+)(RE=Eu,Ce,Tb)中稀土离子的发光性质  

Luminescent Properties of Rare Earth Ions in Sr_4Al_(14)O_(25)∶RE^(3+) (RE=Eu, Ce, Tb)

作　　者：彭明营[1] 裴治武[1] 洪广言[1] 

机构地区：[1]中国科学院长春应用化学研究所稀土化学与物理重点实验室,吉林长春130022

出　　处：《发光学报》2003年第2期185-188,共4页Chinese Journal of Luminescence

基　　金：国家自然科学基金(20071031);国家自然科学重点基金(29831010)资助项目

摘　　要：采用高温固相反应合成了Sr4Al14O25∶RE3+(RE=Eu,Ce,Tb)样品,研究了其中Eu3+,Ce3+和Tb3+的光谱性质,以及Ce3+与Tb3+共掺时的能量传递现象;发现Eu3+,Ce3+和Tb3+占有两个格位,与Eu2+在此基质中的情况相似;在Tb3+的发射光谱中同时观察到了来自5D3与5D4的发射,表明两能级间无辐射跃迁过程不显著;Ce3+对Tb3+有敏化作用。The phosphors of Sr4Al14O25∶RE3+(RE=Eu, Ce, Tb) were sy nthesized by hightemperature solid state reaction.The doping ions all occupy two different sites in the matrix. The two charge transfer bands and two 5D0→7F0 emission lines in the spectra shows that Eu3+ ions occupy two latticl sites in SrAl14O25∶Eu3+.In the excitatio n spectrum of Sr4Al14O25∶Ce3+, there are two broad bands at 265 and 335nm resp ectively, due to the transitions from the ground states of 2F5/2 and 2F7/2 to the excited state of 5d.Because of the large overlap between the emission band s, we couldn't separate them from each other, even reducing the slit width.We cou l d get two bands at 362 and 385nm with the Gaussianfitted method by origin soft . The energy difference between them is 1 650cm-1, lower than that of 2F5/2 and 2F7/2, viz.2 000cm-1 as usual.The intensity of 385nm band relat ive to that of 362nm in the case of 335nm excitation is stronger than that in th e case of 265nm excitation, which might be due to the energy transfer from t he 362nm band to the 3 85nm band.Similar phenomenon appeared in the phosphor of Sr4Al14O2 5∶Eu2+.In Sr4Al14O25 ∶Tb3+, the emission spectra are different from each other in the cases of the excitations at 235 and 241nm.At the excitation of 235nm, the 382nm ban d is the strongest emission peak, while at the excitation of 241nm, the 545nm one instead of it.The above analyses confirmed that these three ions all had two l ight centers, just like Eu2+ ions in this host.The emissions from the le vels of 5D3 and 5D4 of Tb3+ appear at the same time, whic h shows that the nonradiative process between th

关 键 词：稀土离子 发光性质 Sr4Al14O25 RE^3+ 高温固相反应 无辐射跃迁 能量传递 铝酸锶 发光材料 

分 类 号：TN104.3[电子电信—物理电子学] O482.31[理学—固体物理]