High-Resolution Laser Diagnostics and Modeling of Single-Walled Carbon Nanotube Synthesis by Plasma-Enhanced CVD

等离子体增强 CVD 合成单壁碳纳米管的高分辨率激光诊断和建模

• 批准号: 0828165
• 负责人: Robert Lucht
• 金额: $ 32.74万
• 依托单位: Purdue University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-10-01 至 2012-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0828165&HistoricalAwards=false
• 关键词: Resolution; Laser; Diagnostics; Modeling; Single

CBET-0828165LuchtThis research aims to develop key science for developing controlled synthesis of single-wall carbon nanotubes (SWCNTs) by plasma-enhanced chemical vapor deposition (PECVD). Carbon nanotubes have been shown to produce a wide range of outstanding physical properties with important technical and societal implications. However, some crucial properties depend strongly on material parameters that, to date, have been largely uncontrollable in the synthesis process. Well controlled fabrication of carbon nanotubes could enable breakthroughs across a vast range of applications, including ultrafast field-effect transistors and nanoelectronic circuits, direct energy-conversion processes, field-emission devices, high-temperature superconductors, textile fibers, and high-thermal-conductivity films. In addition, the microwave plasma has potentially very high concentrations of species such as CH3 and C-atom. These species are very important in combustion chemistry, but diagnostic techniques for these species are not well developed. The H2/CH4 plasma is thus of great interest as a testbed for the development of new optical diagnostic techniques.A technique pioneered by the research team aids synthesis by reducing concentration of atomic hydrogen from the growth surface, where they etch SWCNTs even at room temperature. The key is applying a positive electrical bias to the growth surface to repel H+ ions from it. Although the role of atomic H appears to be critical in these new processes, very little is known about the composition of the plasma near the growth surface. Spatially resolved optical measurements and complementary models, to be applied and developed in this work, are critical to understanding the role of species such as atomic H and carbon-containing precursors to CNT synthesis. The knowledge gained in this work is expected to enable the creation of synthesis protocols and models that in turn will aid the longer-term goal of controlled synthesis of CNT materials, structures, and devices. The proposed program will expose mechanical engineering graduate students to additional areas of science and engineering, such as molecular electronics and plasma physics, through existing collaborations with electrical engineers, material scientists, physicists, and chemists. In addition, exciting new research on nanotechnology and laser diagnostics will strongly attract domestic students into science and technology research careers through participation in Purdue's Summer Undergraduate Research Fellowship (SURF) program.

CBET-0828165Lucht该研究旨在开发通过等离子体增强化学气相沉积 (PECVD) 控制合成单壁碳纳米管 (SWCNT) 的关键科学。 碳纳米管已被证明具有多种出色的物理特性，具有重要的技术和社会意义。然而，一些关键特性在很大程度上取决于材料参数，迄今为止，这些参数在合成过程中很大程度上是不可控的。碳纳米管的良好控制制造可以在广泛的应用中实现突破，包括超快场效应晶体管和纳米电子电路、直接能量转换过程、场发射器件、高温超导体、纺织纤维和高热能材料。导电薄膜。此外，微波等离子体可能含有非常高浓度的物质，例如 CH3 和 C 原子。这些物质在燃烧化学中非常重要，但这些物质的诊断技术尚未得到很好的发展。因此，H2/CH4 等离子体作为开发新光学诊断技术的试验台受到了极大的关注。研究小组首创的一项技术通过降低生长表面的原子氢浓度来辅助合成，即使在室温下，它们也可以蚀刻单壁碳纳米管。关键是向生长表面施加正电偏压以排斥 H+ 离子。尽管氢原子在这些新工艺中的作用似乎至关重要，但人们对生长表面附近等离子体的成分知之甚少。这项工作中应用和开发的空间分辨光学测量和补充模型对于理解原子 H 和碳纳米管合成中的含碳前体等物质的作用至关重要。这项工作中获得的知识预计将能够创建合成方案和模型，进而有助于实现 CNT 材料、结构和器件的受控合成的长期目标。拟议的项目将通过与电气工程师、材料科学家、物理学家和化学家的现有合作，让机械工程研究生接触科学和工程的其他领域，例如分子电子学和等离子体物理学。此外，关于纳米技术和激光诊断的令人兴奋的新研究将强烈吸引国内学生通过参与普渡大学的夏季本科生研究奖学金（SURF）计划进入科学技术研究职业。