阳极腐蚀法制备发光多孔硅的正电子湮没研究  

Positron annihilation technique study of porous silicon prepared by anodization methods

作　　者：梁立欢[1,2] 李卓昕[2] 王宝义[2] 吴伟明[1] 

机构地区：[1]广西大学物理科学与工程技术学院,广西南宁530004 [2]中国科学院高能物理研究所核分析技术重点实验室,北京100049

出　　处：《广西大学学报（自然科学版）》2011年第5期863-866,共4页Journal of Guangxi University（Natural Science Edition）

基　　金：国家自然科学基金资助项目(10835006;10705031)

摘　　要：使用正电子湮没寿命谱仪和真空紫外荧光光谱仪,对不同电流密度腐蚀条件下制备的多孔硅进行微结构及发光性能的表征,通过正电子湮没方法研究多孔硅微结构对多孔硅光致发光性能的影响。实验结果表明,随着腐蚀电流密度的增大,电子偶素在样品中的pick-off湮没寿命先增大后减小,同时样品的发光强度显示出相同趋势。可以推断,在腐蚀电流密度增加过程中,样品中硅纳米线尺寸逐渐减小,并且由于腐蚀作用增强而发生断裂,造成多孔硅层崩塌;样品的发光主要来源于纳米颗粒或纳米线的量子限制效应,并在颗粒最小时发光峰最强。Porous silicon（PS） samples prepared under different oxidizing current density are characterized by the positron lifetime spectrometer and VUV spectroscopic,using positron annihilation technique（PAT） study on the photoluminescence properties of PS.The experimental results show that the pick-off lifetime（τ3） first increases along with the increase of the current density,then decreases,and the PL intensity showed the same trend.It was found that in the process of current density increases,the size of nanowires decrease gradually,then rupture because of the enhanced corrosion,resulting in collapse of the porous silicon layer.The results also reveal that the light-emitting of PS is attributed to the quantum confinement effects,and the PL intensity becomes strongest when the size of nanosilicon reduced to the minimum.

关 键 词：多孔硅 正电子湮没 电流密度 量子限制 阳极腐蚀 

分 类 号：O571.1[理学—粒子物理与原子核物理]