面向实用的新颖碳基点电子源的TEM原位构建

项目名称： 面向实用的新颖碳基点电子源的TEM原位构建

项目编号： No.61471307

项目类型： 面上项目

立项/批准年度： 2015

项目学科： 无线电电子学、电信技术

项目作者： 王鸣生

作者单位： 厦门大学

项目金额： 83万元

中文摘要： 碳纳米管因其优越的结构和性能被公认为理想的场发射材料，并有望取代钨阴极成为各种先进仪器的场发射点电子源。然而迄今为止，真正实用的碳管点电子源尚未出现，这主要归因于碳管本身还存在的结构弱点以及加工技术方面的困难。本项目拟采用新兴的原位透射电镜技术来解决这些难题，以推动碳基点电子源的实用化。原位电镜技术不仅可以实现性能和结构的直接对应，还是强大的加工制备手段。利用此技术，我们已经并还将再构造出几种新颖的碳基场发射复合尖端结构：单壁纳米锥/多壁管、巴基葱/钨针尖、少层石墨烯包裹的钨针尖等。这些结构的共同特点是：保留碳管最关键部位，即由sp2碳键构成的高曲率闭合末端，改造或是消除碳管径部。它们的结构更加稳固，场发射稳定性和大电流的承受力显著提高，这也是碳材料成为实用高亮相干电子源的关键。我们将对这些结构的制备工艺、形成机理和场发射性能做深入系统的测试和研究,并通过结构调控使其更接近实用场发射阴极。

中文关键词： 纳米场致发射；纳电子学；碳纳米管；冷阴极；电子发射

英文摘要： Carbon nanotubes are widely accepted as the ideal materials for field emission due to the superiority of their structures and properties. They are even excepted as very promising candidates to take the place of tungsten cathodes in many advanced instruments. To date, however, the CNT-based point electron sources for real applications are not yet available, mainly attributed to the structural weakness of CNT itself, as well as the difficulties during the materials fabrication and processing. This project aims to solve the problems mentioned above via the newly-developed in-situ transmission electron microscopy (TEM) techniques, so as to achieve the real application of carbon point electron sources. In-situ TEM technique provides not only the direct correlation between structures and properties, but a powerful tool for nanostructure fabrication. By using this technique, we have and will create some novel carbon-based field emitters with combined structures: single-walled nanocone/ multiwalled nanotube, carbon-onion/W-tip, and few-layer graphene encapsulating a W tip, etc. All these new structure share the same feature: they possess the most crucial part of a CNT,i.e. the highly curved closed end consisting of sp2 C-C bonds, but the CNT shank has been modified or even completely removed. These structures are supposed to be more stable, and the field emission stability and the capability to carry large emission current should be remarkably improved. This is actually the key issues for a practical electron source with high brightness and better coherence. We are planning to carry out thorough tests to investigate the fabrication techniques, formation mechanism, and field emission properties of these novel structures. Through structural tailoring of these carbon electron sources, better performance will be achieved to make them the practical field emitters.

英文关键词： nanoscale field emission;nanoelectronics;nanotubes;cold cathode;electron emission