Eu^(3+)在LiSrPO_4中的发光及浓度猝灭机理  

Luminescence and Concentration Quench Mechanism of Eu^(3+) in LiSrPO_4

作　　者：杨志平[1] 王凤和[1] 李盼来[1] 刘玉峰[1] 

机构地区：[1]河北大学物理科学与技术学院,保定071002

出　　处：《硅酸盐通报》2010年第2期431-435,共5页Bulletin of the Chinese Ceramic Society

基　　金：河北省自然科学基金(F2009000217)资助项目

摘　　要：采用高温固相法合成了白光发光二极管用LiSrPO4∶Eu3+红色荧光粉。测量了LiSrPO4∶Eu3+的激发和发射光谱,结果显示材料的发射光谱为一系列尖峰,主峰位于616nm,具有很强的红光发射;激发光谱中O2-→Eu3+的电荷迁移态CTS(220～310nm)非常低,Eu3+的f→f(310～500nm)跃迁吸收很强,主峰位于393nm,与InGaN(350～410nm)管芯匹配。比较了LiSrPO4∶Eu3+与LiCaPO4∶Eu3+、LiBaPO4∶Eu3+发射光谱的差异,这三种晶体中Eu3+占据的格位对称性按Ca、Sr、Ba顺序逐渐增加。根据Dexter理论判定Eu3+在LiSrPO4中的浓度猝灭机理为电四极-电四极(q-q)相互作用。加入电荷补偿剂Li+、Na+和Cl-均提高了LiSrPO4∶Eu3+材料的发射强度。LiSrPO4∶Eu3+是一种适合白光发光二极管激发的红色荧光粉。The red phosphor LiSrPO4： Eu3＋ for white LEDs was synthesized by high temperature solid state reaction. The emission and excitation spectra were investigated. The emission spectra showed a series of sharp peaks, in which the strongest one appeared at 616 nm. The excitation spectrum monitored at 616 nm contained two excitation bands, weak charge transition band absorption CTS （220-310 nm） and strongf--＊ftransition absorption （310-500 nm） of Eu3＋. The strongest peak located at 393 nm which was coupled well with the emission of InGaN （350-410 nm）. There were some differences in emission spectra of Eu3 ＋ in LiCaPO4, LiSrPO4 and LiBaPO4. The symmetry of crystal lattice sites which Eu3 ＋ occupied were enhanced by order of Ca, Sr, Ba. Concentration quenching occurred as a result of quadrupole-quadrupole interaction according to Dexterg theory. Li ＋ , Na ＋ and Cl- could all enhance the light emit intensity when used as charge compensations. The LiSrPO4： Eu3＋ phosphor was a potential red- emitting phosphor for white LEDs.

关 键 词：白光LED LiSrPO4∶Eu3+ 浓度猝灭 

分 类 号：O644[理学—物理化学]