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arXiv 1412.7622cond-mat.mes-hall
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单个空气悬浮碳纳米管中激子扩散、末端淬灭和激子-激子湮灭

Exciton diffusion, end quenching, and exciton-exciton annihilation in individual air-suspended carbon nanotubes

A. Ishii, M. Yoshida, Y. K. Kato

摘要:

激子扩散对碳纳米管的发光特性有很大的影响,它在各种非辐射衰减过程中起着重要的作用。在这里,我们进行光致发光显微镜数百个单独的空气悬浮的碳纳米管,以阐明激子扩散,末端淬火,激子-激子湮灭过程之间的相互作用。利用随机游走理论和蒙特卡罗模拟建立的模型分析了纳米管长度和激发功率对发光强度的影响。我们得到了不同手性的激子扩散长度和吸收截面的值,并观察到了光致发光量子产率随直径的变化。模拟还揭示了一维聚结过程的本质,并给出了发射强度与功率关系的解析表达式。

英文摘要:

Luminescence properties of carbon nanotubes are strongly affected by exciton diffusion, which plays an important role in various nonradiative decay processes. Here we perform photoluminescence microscopy on hundreds of individual air-suspended carbon nanotubes to elucidate the interplay between exciton diffusion, end quenching, and exciton-exciton annihilation processes. A model derived from random-walk theory as well as Monte Carlo simulations are utilized to analyze nanotube length dependence and excitation power dependence of emission intensity. We have obtained the values of exciton diffusion length and absorption cross section for different chiralities, and diameter-dependent photoluminescence quantum yield have been observed. The simulations have also revealed the nature of a one-dimensional coalescence process, and an analytical expression for the power dependence of emission intensity is given.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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