(Ce,Tb) MgAl11O19绿色荧光粉的发光性质和能量传递

在还原气氛下,采用高温固相法合成了(Ce, Tb) MgAl11O19绿色荧光粉,研究了(Ce, Tb) MgAl11O19中Ce3 与Tb3 发光性质和两者之间的能量传递现象.Ce3 的发射光谱表明Ce3 由于5d轨道裸露在外壳层,很容易受到周围晶体场的影响,使得5d轨道不再是分离的能级,几乎成为能带,从而造成了Ce3 的宽带发射而不是线谱.Ce3 的发射光谱与Tb3 的激发光谱在350-450nm范围内有很大的光谱重叠,从而为两者之间的能量传递提供了良好的条件.Ce3 与Tb3 之间的能量传递方式主要以共振传递为主.

LUMINESCENCE AND ENERGY TRANSFER IN (Ce,Tb)MgAl11O19

A series of compounds activated by Tb~(3+), such as rare earth oxide, aluminate phosphate and so on, can emit green light. It is important to look for an efficient path of energy transfer in order to enhance their brightness and reduce the content of Tb farther. (Ce, Tb) MgAl_(11)O_(19) phosphor was synthesized by high temperature solide state reaction method. The emission and excitation spectra and energy transfer of Ce~(3+) and Tb~(3+) in (Ce, Tb) MgAl_(11)O_(19) were investigated. The emission spectrum of Ce~(3+) indicates that Ce~(3+) ion easy to be affected by the surroundings owing to the bareness of 5d orbits, leading to the 5d state is no longer the detached energy level, almost becomes energy band. So the emission of Ce~(3+) is not line spectrum but broadband emission. The emission spectra of Ce~(3+) and the excitation spectra of Tb~(3+) have large superposition at 350-450nm regions, which supply good conditions for energy transfer between Ce~(3+) and Tb~(3+). The energy transfer between Ce~(3+) and Tb~(3+) is primarily as resonance transfer.