Length-Dependent Photoluminescence Lifetimes in Single-Walled Carbon Nanotubes
Length-Dependent Photoluminescence Lifetimes in Single-Walled Carbon Nanotubes
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DOI：
10.1021/jp1027492
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发表时间：
2010-07
影响因子：
3.7
通讯作者：
Y. Miyauchi;K. Matsuda;Yuki Yamamoto;N. Nakashima;Y. Kanemitsu
中科院分区：
文献类型：
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作者：
Y. Miyauchi;K. Matsuda;Yuki Yamamoto;N. Nakashima;Y. Kanemitsu
我们用时间分辨光致发光(PL)激发相关谱描述了DNA包裹的单壁碳纳米管(SWNTs)中的长度相关激子动力学。我们证明，在较长的单壁碳纳米管中，有效发光寿命有相当大的上限。我们的结果表明，激子扩散到纳米管末端对净无辐射弛豫率的贡献是有限的，而激子到达单壁碳纳米管末端之前发生的非辐射过程是对非辐射寿命的主要贡献。从单壁碳纳米管的荧光寿命和相对强度随长度变化的数据来看，激子扩散长度为∼50 nm，扩散系数为∼1 cm~2/S。
We describe the length-dependent exciton dynamics in DNA-wrapped single-walled carbon nanotubes (SWNTs) using time-resolved photoluminescence (PL) excitation correlation spectroscopy. We demonstrate that the effective PL lifetimes have substantial upper limits in longer SWNTs. Our results suggest that the exciton diffusion to the ends of the nanotube has only a limited contribution to the net nonradiative relaxation rate, and the nonradiative processes that occur before the excitons reach the ends of SWNT are the dominant contribution to the nonradiative lifetime. From the length-dependent PL lifetimes and relative intensities in DNA-wrapped SWNTs, the exciton diffusion length was found to be ∼50 nm, and the diffusion coefficient was ∼1 cm2/s.