氧对LaOX：Ce3+和MFX：Ce3+体系猝灭作用的光谱研究

本文首次报道了LaOX:Ce3+和MFX:Ce3+(X=Cl-,Br-;M=Ba2+,Sr2+系列的光声光谱特性,并通过与荧光光谱的对照研究,讨论了氧对Ce3+在MFX和MF2(M=Ba2+,Sr2+基质中发光的猝灭作用.发现样品的发光随灼烧时间的加长而减弱,光声信号却依次增强,表明空气中氧对Ce3+发光的猝灭表现在其无辐射跃迁几率增加.同时发现由于非氟卤素的引入,便得MFX:Ce3+比MF2:Ce3+的抗淬灭性增强.文中着重研究了Ce3+在MFX基质中的发光,结果表明,在无氧合成条件下,MFX:Ce3+中Ce3+以发光中心Ⅱ(420nm附近)为主.

THE PAS AND PL SPECTRUM IN THE QUENCHING EFFECTS OF O_2 ON LaOX:Ce~(3+) AND MFX:Ce~(3+) SYISTEMS

The photoacoustic spectroscopy(PAS) has been widely used to study the non-radiation transition process for fluorescent materials in solid state especially. The PAS in LaOX:Ce3+ and MFX:Ce3+ (X=C1-,Br-;M=Ba2+,Sr2+) are first reported in this paper. By comparing with fluorescent spectra of these samples,the quenching effects of O2 on Ce3+ in MFX and MF2(M=Ba2+,Sr2+) matrixes are discussed. It has shown that with the longer sintering time,the luminescent intensity decreases,whereas the signal of PAS is getting stronger and stronger accordingly. PAS expriments have also shown that the remaining trace oxygen (O2) quenched the emission of Ce3+ ion doped in MFX matrixes mainly through increasing the non-radiation transition probability of Ce3+ ,and because of the doping of non-fluorine halogen,MFX:Ce3+ systems posses higher resistance to quench than pure fluoride systems MF2 :Ce3+. Additional,the luminescent center of Ce3+ in MFX matrixes is mainly center I (near 420nm)on this condition of non-oxygen syntheses.