“格致论坛”第十九讲

信息来源:88858cc永利官网学院办公室   点击次数:  发布时间:2013-04-24

一、题目:单壁碳纳米管中激子扩散长度评价

二、报告人:谢建平

三、日期:2013年4月24日(星期三)下午3:30

四、地点:闻理园A4-222

主讲人简介:谢建平博士,2009毕业于浙江大学物理系,获凝聚态物理专业博士学位,导师叶高翔教授。2009年至2012年赴日本东京理科大学,在物理系从事博士后研究工作。近年来,在Phys. Rev. B等国际权威的物理学期刊上发表学术论文近十篇,在纳米薄膜、纳米碳管、石墨烯等材料的制备方法中积累了很好的研究基础。

报告摘要:Direct evaluation of the intrinsic exciton diffusion length in a long single walled carbon nanotube (SWNT) is reported by analyzing the tube length dependence of photoluminescence (PL) emission intensity. The PL emission intensities depending on the tube length are obtained from a single long-SWNT suspended on a groove-patterned quartz substrate. The exciton diffusion behavior is described by one dimensional diffusion equation and the intrinsic diffusion length in these clean and pristine long SWNTs is found to be about 300 nm at lower laser regime indicating an intrinsic exciton diffusion behavior. The critical laser power value in our experiment where the exciton-exciton annihilation (EEA) effect begins to affect the diffusion length is also analyzed.

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