LaOBr:Ce,Tb中Ce3+对Tb3+发光的影响

近年来人们对LaOBr:Tb的合成及其发光特性的研究日益增多。LaOBr:Tb不仅是良好的X光增感屏材料,也是较好的阴极射线发光材料。为了进一步提高它的亮度,降低了b的含量(因Tb很贵),寻求LaOBr中Tb3+发光的敏化剂是很重要的。

THE EFFECT OF Ce3+ ON Tb3+ LUMINESCENCE IN LaOBr:Tb3+,Ce3+

The luminescence of LaOBr:Ce,LaOBr:Ce,Tb and LaOBr:Tb phosphors under UV and cathode ray excitation has been studied.The excitation spectra of Tb3+ ion in LaOBr:Tb consists of a strong broad 4f→5d transition band at 254nm and some weak 4f→4f transition lines in the wavelength range of 300-400nm.The excitation bands of LaOBr:Ce at 352.5,314.5 and 289nm originate from transition between the 4f-ground state(7F)and the 5d-excited state(2D).The excitation spectrum of Tb3+ ion in LaOBr:Ce3+,Tb3+ consists of four bands at 254,289,314.5 and 352.5nm due to Tb3+ and Ce3+.It is clear that only the excitation bard at 254nm belong to Tb3+ ions and the other three bards are the excitation bands of Ce3+ ion.With increasing Ce3+ concentration the intensity of Tb3+ excitation band at 254nm decreases,at the same time the intensities of the Ce3+ excitation bands at 289,314.5 and 352.5nm increase.