Polarization dependent optical absorption properties of single-walled carbon nanotubes and methodology for the evaluation of their morphology
Polarization dependent optical absorption properties of single-walled carbon nanotubes and methodology for the evaluation of their morphology
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DOI：
10.1016/j.carbon.2005.05.036
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发表时间：
2005-11-01
期刊：
影响因子：
10.9
通讯作者：
Maruyama, S
中科院分区：
文献类型：
--
作者：
Murakami, Y;Einarsson, E;Maruyama, S
研究了单壁碳纳米管在0.5 ~ 6 eV能量范围内的光吸收特性的偏振依赖性。我们发现紫外区的吸收峰在大约4.5和5.25 eV处与SWNT薄膜的形态或相对于SWNT轴的入射光偏振表现出显著的不同依赖性。在考虑平行和垂直于SWNT轴的过渡偶极子的情况下，建立了一种分析途径来评估垂直排列的SWNT薄膜的SWNT定向物理程度。该分析过程，再加上对生长在衬底上垂直排列的SWNT薄膜进行的偏振光吸收测量，可以确定平行于SWNT轴和垂直于SWNT轴的SWNT裸光吸收截面。最后，应用所提出的评价SWNT薄膜形貌的方法来研究垂直排列SWNT薄膜生长过程中排列度的瞬态变化。(C) 2005 Elsevier Ltd版权所有。
Polarization dependence of-the optical absorption properties of SWNTs is presented and investigated in detail for the energy range 0.5-6 eV. We found that the absorption peaks in the UV region at approximately 4.5 and 5.25 eV exhibit remarkable and different dependencies on the morphology of the SWNT film, or equivalently, on the incident light polarization relative to the SWNT axis. An analytical pathway to evaluate the physical degree of SWNT alignment for a vertically aligned SWNT film is developed with both transition dipoles parallel and perpendicular to the SWNT axis taken into account. This analytical procedure, coupled with polarized optical absorption measurements performed on the vertically aligned SWNT film grown on substrates, leads to the determination of the bare optical absorption cross-section of SWNTs for both parallel and perpendicular to SWNT axis. In the end, the proposed methodology for evaluating the SWNT film morphology is applied to investigate the transient change of the degree of alignment in the growth process of our vertically aligned SWNT films. (C) 2005 Elsevier Ltd. All rights reserved.