悬浮单根纳米碳管端部场分布的计算

Calculation of Field Distribution on Hemispherical Apex of Single Carbon Nanotube Emitter

本文以建立的悬浮纳米碳管头部模型替代整根纳米碳管,来研究影响阴阳极板间单根纳米碳管顶端的场强变化的不同参数。运用模拟电荷和镜像电荷导出单根纳米碳管尖端场增强因子关于长径比的简单线性公式,其结果明显优于悬浮球模型。利用此模型同时可得到相应的顶端电场分布,结果表明其分布并不明显依赖纳米碳管的长径比,而且纳米碳管柱面的场发射电流微弱,与顶端的场发射电流相比可以忽略。

The field distribution on the hemispherical apex of a single carbon nanotube field emitter was calculated. The pseudo-charges and image-charges were assumed in the calculation. And the approximated linear dependence of the field enhancement factor on the aspect ratio of the carbon nanotube field emitter was derived. The results show that the aspect ratio of the carbon naotube has little impact on the field distribution on the hollow hemispherical apex, and that the current emitted from the apex surface is much stronger than that from the side walls of the carbon nanotube.