不同类型掺杂剂对AgCl微晶中光电子衰减特性影响

Effect of different dopants on photoelectrons decay characteristic in AgCl microcrystals

电子陷阱掺杂可明显改善晶体材料中光电子衰减特性,最终改善其物理性能。利用微波吸收介电谱检测技术,对30%Ag位置处掺杂不同浓度K4[Ru(CN)6]和(NH4)2IrCl6的立方体AgCl微晶中自由和浅束缚光电子衰减时间(FDT,SDT)分辨谱进行了检测。结果表明,对于掺杂K4[Ru(CN)6]的样品,随掺杂浓度增加,FDT逐渐从157ns延长至520ns;且不同浓度掺杂时的FDT均大于未掺杂时的FDT(150ns)。而对于掺杂(NH4)2IrCl6的情况,随掺杂浓度增加,FDT逐渐从126ns减小至45ns;且不同浓度掺杂时的FDT均小于未掺杂时的FDT(150ns)。分析得知,K4[Ru(CN)6]掺杂在AgCl中引入了能暂时俘获光电子的浅电子陷阱(SETs);而(NH4)2IrCl6掺杂在AgCl中引入了能长时间俘获光电子的深电子陷阱(DETs)。同时对光电子衰减动力学过程分析得知,陷阱的类型对光电子衰减寿命分区影响不同,SETs的引入使光电子衰减寿命曲线明显呈现两个指数衰减区,而DETs的引入使光电子衰减寿命曲线只呈现一个指数衰减区。

Electron trap dopants can obviously improve the photoelectrons decay characteristic and thus improve the physical performance of the microcrystal materials. By microwave absorption and dielectric spectrum measure technique,the decay spectra of the free and shallow-trapped photoelectrons in cubic AgCl microcrystals doped with different contents of K4 [ Ru（CN） 6 ] and （ NH4 ） 2 IrCl6 at 30 % Ag are obtained. The results show that as for IQ [Ru（CN）6 ] doping, with the doping content increasing, the free photoelectrons decay time gradually increases from 157 ns to 520 ns, and the free photoelectrons decay time for all the doped samples is longer than that of the undoped samples. But for （NH4）z IrC16 doping, with the doping content increasing,the free photoelectrons decay time gradually decreases from 126 ns to 45 ns, and the free photoelectrons decay time for all the doped samples is shorter than that of the undo- ped samples. By analysis, the K4 [-Ru（CN）6] doping introduces shallow electron traps which can trap photoelectrons temporarily,but the （NH4）~ IrC16 doping introduces deep electron traps which can trap photoelectrons for longer time in AgC1. By analyzing the photoelectrons decay kinetics,it is obtained that the types of dopants have different effects on decay section of the photoelectrons. Two first-order expo- nential decay sections occur as for the introduction of shallow electron traps but one for the deep electron traps.