ZnS晶体中浅电子陷阱对光电子衰减过程的影响

本文采用微波吸收法,测量了ZnS:Mn,Cu:I,Br粉末材料受到超短激光脉冲激发后,其光生电子和浅束缚电子的衰减过程.发现制备过程中Mn2+、Cu1、I-、Br-的掺杂量对光生导带电子的衰减过程有明显的影响.光生电子寿命是I-、Br-形成的浅施主能级和Cu+受主能级、Mn2+发光中心共同作用的结果.本文还测量了材料的热释光曲线,Cu+受主能级、Mn2+发光中心会影响热释光强度,证实I-、Br-形成电子陷阱对光生电子和浅陷阱中的电子寿命有延长作用,而Mn2+发光中心会起到缩短寿命的作用.

Effect of Shallow Electron Traps on the Decay Process of Photoelectron in ZnS Crystals

The decay process of photogenerated charge carriers of ZnS:Mn,Cu:I,Br luminescence materials after excitation with short pulse laser was investigated by using microwave absorption dielectric spectrum detection technique in this paper.It is found that the concentration of Mn~(2+),Cu~+,I~-,Br~- dopant has a great influence on the lifetime of electrons in conduction band.The lifetimes of electrons are determined by the synergistic action of the shallow donor energy level formed by I~- and Br~-,Cu~+ acceptor energy level and Mn~(2+) luminescence center.In addition,the thermoluminescence spectra of ZnS:Mn,Cu:I,Br luminescent materials were measured.Cu~+ acceptor energy level and Mn~(2+) luminescence center have an effect on the intensity of thermoluminescence spectra.It has been proved that the electron traps formed by I~- and Br~- prolonged the lifetimes of photoelectrons and shallow-trapped electrons, while Mn~(2+)luminescence centers shortened the lifetimes of photoelectrons and shallow-trapped electrons.