SrS:Eu与SrS:Eu,Sm中电子陷阱与光存储研究

对SrS:Eu和SrS:Eu,Sm激发初始阶段的荧光上升过程和余辉进行了研究，并进一步考证其中 电子陷阱的属性.通过两种样品和两个阶段的比较，对陷阱数量和深度的变化、量子效率以 及电子俘获和释放、复合过程进行了分析，发现Sm离子并不影响陷阱的数量.利用吸收光谱 方法研究了SrS:Eu,Sm中电子由陷阱能级向导带的跃迁.通过陷阱饱和-倒空吸收谱差，即激 励吸收谱及其强度随Eu,Sm浓度的变化，探讨了掺杂浓度对陷阱浓度和光存储饱和量的影响. 结果表明Sm离子的作用是使陷阱能级加深从而能稳定地储存电子.通过激励吸收谱峰值强度 可确切地比较光存储材料在这方面的性能，并与光激励谱的测量方法作了对照. 关键词： 电子陷阱 光存储 电子俘获 光激励发光

ELECTRON TRAP AND OPTICAL STORAGE STUDIES IN SrS:Eu AND SrS:Eu,Sm

The electron traps in SrS:Eu and SrS:Eu, Sm were studied by the time dependence of their afterglow and the fluorescence rising process at the beginning of excitation. The numbers of traps in both phosphors were compared and the singly doped SrS:Eu was found to have approximately the same trap number as the latter at the absence of Sm inos. The absorption spectra of SrS:Eu,Sm at excited and bleached states were measured respectively. The difference at infrared region between them demonstrates the transitions of electrons from the traps to conduction band, which were studied by stimulated spectrum normally. The concentration dependence of Eu and Sm of this difference that we named stimulating absorption spectrum was examined. The results show that the complexes formed by combination of Sm ions and crystal defects such as anion impurity ions or vacancies act as the storageable traps, i.e.,Sm ions play a role of deepening the trap levels so that the trapped electrons can be stored stably.