Molecular Spectroscopy of Carbon Nanotubes

碳纳米管的分子光谱

• 批准号: 0405538
• 负责人: Mildred Dresselhaus
• 金额: --
• 依托单位: Massachusetts Institute of Technology
• 依托单位国家: 美国
• 项目类别: Continuing grant
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-07-01 至 2007-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0405538&HistoricalAwards=false
• 关键词: Molecular; Spectroscopy; Carbon; Nanotubes

The objective of this project is to advance the spectroscopy of single wall carbon nanotubes (SWNTs) in a major way by studying new phenomena in their discovery phase, by examining controversial and unresolved issues concerning spectroscopic phenomena associated with the one-dimensionality of carbon nanotubes, and by developing new capabilities for studying the spectroscopy of carbon nanotubes. The approach is to focus on four topics: 1) experimentally elucidate the newly discovered unusual phenomena associated with combination modes in the resonance Raman spectra in the intermediate frequency range of 600-1100 cm-1 where new turn-on/turn-off phenomena are observed, as the laser excitation energy is varied, and then explaining the physics behind the newly observed phenomena; 2) develop a strategy for resolving through experimental investigation of the two seemingly different interpretations for the fundamental mechanism responsible for the dominant G-band spectral features in single wall carbon nanotubes, namely, whether these features are due to first-order scattering processes or to double resonance processes. According to this strategy, conditions favorable for the study of the two processes will be created so that their interrelation can be studied quantitatively; 3) improvement of the signal-to-noise in Raman spectroscopy measurements at the single nanotube level by developing techniques for measuring spectra on freely suspended individual single wall nanotubes. This research is expected to experimentally resolve phenomena that were previously buried in the noise and thus to open up new research directions; 4) develop a strategy for gaining an understanding of the relationship between the singularities in the electronic density of states as observed in single molecule Raman scattering and in photoluminescence, by systematically carrying out the two types of studies on the same individual nanotubes. Measurements on both bundles of SWNTs and on individual SWNTs will be carried out. At present, the two techniques give results that appear to differ regarding both the values of the resonant energies that have been reported and the spread of the ensemble of resonant energies observed at constant diameter.%%% The project addresses basic research issues in a topical area of materials science with high technological relevance. An important feature of the program is the integration of research and education through the training of students and postdoctoral researchers in a fundamentally and technologically significant area. The project assists development of technical, communication, and organizational/management skills in students through unique educational experiences made possible by a highly collaborative forefront research environment. The research is expected to have broad impacts through the training of young men and women leaders in the field, by the wide dissemination of the findings of this research through invited talks and publications, and through the preparation of tutorial review articles to interrelate the work of various researchers in the field, and to identify future research areas of importance and promise. The principal investigator and her students will continue to disseminate advances in nanoscience and nanotechnology to the public through invited talks to general audiences, and through advisory work for the government, industrial laboratories, universities and professional societies.***

该项目的目标是通过研究发现阶段的新现象，通过研究与碳纳米管一维性相关的光谱现象有关的有争议和未解决的问题，以及通过开发研究碳纳米管光谱的新能力，以主要方式推进单壁碳纳米管（SWNTs）的光谱学。主要研究四个问题：（1）在600-1100 cm ~（-1）的中频范围内，在共振拉曼谱中观察到新的组合模随激光激发能量变化的开启/关断现象，并从实验上解释这些现象背后的物理机制; 2）发展一种策略，通过实验研究解决对单壁碳纳米管中占主导地位的G带光谱特征的基本机制的两种看似不同的解释，即这些特征是由于一阶散射过程还是双共振过程。根据这一战略，将创造有利于这两个过程的研究，使它们的相互关系可以定量研究的条件; 3）改善的信号-噪声在拉曼光谱测量在单纳米管水平的发展技术，用于测量光谱上自由悬浮的单个单壁纳米管。这项研究有望在实验上解决以前被埋在噪声中的现象，从而开辟新的研究方向; 4）通过系统地对同一个单独的纳米管进行两种类型的研究，开发一种策略，用于理解在单分子拉曼散射和光致发光中观察到的电子态密度中的奇异性之间的关系。将对两束单壁碳纳米管和单个单壁碳纳米管进行测量。目前，这两种技术给出的结果似乎在已报道的共振能量值和在恒定直径下观察到的共振能量系综的分布方面都不同。该项目涉及材料科学专题领域的基础研究问题，具有高度的技术相关性。该计划的一个重要特点是通过在一个基本和技术重要的领域培养学生和博士后研究人员来整合研究和教育。该项目通过高度协作的前沿研究环境，通过独特的教育经验，帮助学生发展技术，沟通和组织/管理技能。预计这项研究将产生广泛的影响，通过培训该领域的青年男女领导人，通过邀请演讲和出版物广泛传播这项研究的结果，并通过编写指导评论文章，使该领域的各种研究人员的工作相互关联，并确定未来的重要研究领域和前景。首席研究员和她的学生将继续通过邀请普通观众进行演讲以及为政府、工业实验室、大学和专业协会提供咨询工作，向公众传播纳米科学和纳米技术的进展。*