摘要
采用高温固相法制备了Eu3+离子激活的Ca9R(VO4)7(R=Y,La,Gd)红色发光粉,并利用荧光光谱对发光粉的特性进行研究。激发光谱中,Ca9Y(VO4)7∶Eu3+,Ca9La(VO4)7∶Eu3+和Ca9Gd(VO4)7∶Eu3+都有两个宽的VO43-激发带和Eu3+的特征激发峰。发射光谱中,在Ca9Y(VO4)7∶Eu3+和Ca9La(VO4)7∶Eu3+中的350～550nm范围内出现VO43-的发射带,而在Ca9Gd(VO4)7∶Eu3+中却没有观察到VO43-的发射。在这三种发光粉中,Ca9Gd(VO4)7∶Eu3+的发光强度远远高于其它两种,这是由于Gd3+的存在有效地使能量通过Gd3+→VO43-→Eu3+及Gd3+→Eu3+的两种方式进行能量传递,从而提高了Eu3+发光效率。
The red phosphors of Ca9R （ VO4 ） 7 ： Eu^3＋ （ R = Y, La, Gd） were prepared by high temperature solid state reaction method. The structures of these powders were recorded by X-ray powder diffraction. The excitation and emission spectra were recorded by F-4500 spectrofluorometer. The photolumineseence properties were investigated in this paper. The excitation spectrum of Ca9Y （VO4 ）7： Eu^3＋ shows two broad absorption bands in the range of 200 - 350 nm with maximum centered at 254 nm and 320 nm, respectively. The former corresponds to CTS of VO4^3- complex and the latter corresponds to an overlap of both CTS of VO4^3- complex ion and Eu-O CTS band, and also displays sharp absorption lines of f-f transition of Eu^3＋ ion located at 398 nm （^7F0→^5L6） , 467 nm （ ^7F0→^5D2 ） , and 538 nm （^7F0→^5D1 ）, respectively. The excitation spectrum of Ca9La- （VO4）7： Eu^3＋ is similar to that of Ca9Y（VO4）7： Eu^3＋ In Ca9Gd（WO4）7： Eu^3＋ , the excitation spectrum also shows two broad bands centered at 274 nm and 331 nm, respectively,which mainly corresponds to the CTS of VO4^3- complex ion. The photoluminescence spectra of Ca9Y （ VO4 ） 7 ： Eu^3 ＋ and Ca9La （ VO4 ） 7 ： Eu^3 ＋ exhibit broad emission of VO4^3- complex ion and some sharp lines due to the transition of 5 DJ （J = 0,1 ） → ^7 FJ （ J = 1,2, 3, 4） in Eu^3＋ ion. With increasing concentration of Eu^3＋ ions, the emission of VO4^3- is decreased compared tothe transition of 5DJ→^7FJ（J =1, 2, 3, 4） in Eu^3＋ ion. However, the emission of VO4^3- is not exhibited in Ca9Gd- （VO4）7： Eu^3＋ Only the transitions of 5DJ→^FJ（J = 1,2, 3, 4） of Eu^3＋ ion are observed in this compound. The intensity of luminescence is observed much stronger than that of Ca9 Y （VO4）7： Eu^3＋ and Ca9 La（ VO4 ）7： Eu^3 ＋ because two kinds of energy transfer processes of Gd3^＋→ VO4^3- → Eu^3 ＋ and Gd^3 ＋→ Eu^3 ＋ are occurred. Thus, it was resulted that the luminescence eff
出处
《发光学报》
EI
CAS
CSCD
北大核心
2009年第6期768-772,共5页
Chinese Journal of Luminescence
基金
国家教育部留学回国人员科研启动基金(教外司留[2007]1108)资助项目
