High brightness electron beam from a multi-walled carbon nanotube
High brightness electron beam from a multi-walled carbon nanotube
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DOI：
10.1038/nature01233
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发表时间：
2002-11-28
期刊：
影响因子：
64.8
通讯作者：
Oosterkamp, TH
中科院分区：
文献类型：
--
作者：
de Jonge, N;Lamy, Y;Oosterkamp, TH
碳纳米管可以作为电子源（1），具有非常刚性的结构（2），使它们特别适合用作高分辨率电子束仪器中的点电子源。关于这些应用的一些重要要求，已经报道了有希望的结果：稳定的发射电流（3，4，5）和长寿命（6），（7）。电子源的两个参数会影响这些仪器的分辨率：发射电子的能量分布和称为约化亮度的参数，约化亮度取决于角电流密度和虚源大小。几位作者测量了与电子发射相关的低能量扩散（3、7、8、9）。在这里，我们测量降低的亮度，并找到一个值，这是一个超过一个因素的10倍以上，比提供的最先进的电子显微镜的电子源。此外，我们表明，一个单独的多壁碳纳米管发射到一个单一的窄光束的电流。在这些结果的基础上，我们预计，碳纳米管电子源将导致高分辨率电子束仪器的性能显着改善。
Carbon nanotubes can act as electron sources(1) with very rigid structures(2), making them particularly interesting for use as point electron sources in high-resolution electron-beam instruments. Promising results have been reported with respect to some important requirements for such applications: a stable emitted current(3,4,5) and a long lifetime(6),(7). Two parameters of an electron source affect the resolution of these instruments: the energy spread of the emitted electrons and a parameter called the reduced brightness, which depends on the angular current density and the virtual source size. Several authors have measured a low energy spread associated with electron emission(3,7,8,9). Here we measure the reduced brightness, and find a value that is more than a factor of ten larger than provided by state-of-the-art electron sources in electron microscopes. In addition, we show that an individual multi-walled carbon nanotube emits most current into a single narrow beam. On the basis of these results, we expect that carbon nanotube electron sources will lead to a significant improvement in the performance of high-resolution electron-beam instruments.