Influences of Exciton Diffusion and Exciton-Exciton Annihilation on Photon Emission Statistics of Carbon Nanotubes.
Influences of Exciton Diffusion and Exciton-Exciton Annihilation on Photon Emission Statistics of Carbon Nanotubes.
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DOI：
10.1103/physrevlett.115.017401
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发表时间：
2015-02
影响因子：
8.6
通讯作者：
Xuedan Ma;O. Roslyak;J. Duque;Xiao-feng Pang;S. Doorn;A. Piryatinski;D. Dunlap;H. Htoon
中科院分区：
文献类型：
--
作者：
Xuedan Ma;O. Roslyak;J. Duque;Xiao-feng Pang;S. Doorn;A. Piryatinski;D. Dunlap;H. Htoon
在室温下对单个单壁碳纳米管进行了泵浦光致发光成像和二阶光子相关研究。这些研究使激子扩散常数和俄歇复合系数的提取。这些参数之间的线性相关性归因于环境无序的影响，在此长度尺度设置激子平均自由程和捕获限制俄歇复合。光子反聚束的抑制归因于在单壁碳纳米管中产生多个空间不重叠的激子，其扩散长度小于激光光斑尺寸。我们的结论是，在室温下完全反聚束需要增强激子-激子湮灭率，这可能成为可实现的单壁碳纳米管允许强激子本地化。
Pump-dependent photoluminescence imaging and second-order photon correlation studies have been performed on individual single-walled carbon nanotubes (SWCNTs) at room temperature. These studies enable the extraction of both the exciton diffusion constant and the Auger recombination coefficient. A linear correlation between these parameters is attributed to the effect of environmental disorder in setting the exciton mean free path and capture-limited Auger recombination at this length scale. A suppression of photon antibunching is attributed to the creation of multiple spatially nonoverlapping excitons in SWCNTs, whose diffusion length is shorter than the laser spot size. We conclude that complete antibunching at room temperature requires an enhancement of the exciton-exciton annihilation rate that may become realizable in SWCNTs allowing for strong exciton localization.