一种平行栅碳纳米管阵列阴极的场发射特性研究

建立一种平行栅碳纳米管阵列阴极，利用悬浮球模型和镜像电荷法进行计算，给出碳纳米管顶端表面电场与电场增强因子的解析式. 在此基础上，进一步分析器件各类参数以及接触电阻对阴极电子发射性能的影响. 分析表明，碳纳米管间距大约为2倍碳纳米管高度时阵列阴极的分布密度最佳，靠边缘部位的碳纳米管发射电子能力比其中心部位的大；除碳纳米管的长径比之外，栅极宽度和栅极间距也对电场增强因子有一定作用；接触电阻的存在大幅度降低碳纳米管顶端表面电场与发射电流，而接触电阻高于800 kΩ时，器件对阳极驱动电压的要求更高. 关键词： 平行栅碳纳米管阵列 悬浮球 场增强因子 接触电阻

Field emission properties from a carbon nanotube array with parallel grid

One of the models for the carbon nanotube array with parallel grids is proposed. The actual electric field at the top of the carbon nanotubes and the field enhancement factor are calculated analytically with the image charge method and floated sphere model. The effects of the geometrical parameters of the device and the contact resistance on actual electric field, field enhancement factor at the top of carbon nanotubes, and the field emission current from the gated carbon nanotubes are investigated. The calculation results show that the carbon nanotube array has the best density for field emission when the intertube distance is twice the height of carbon nanotube. The actual electric field and the field emission current from gated carbon nanotube are greatly reduced by the contact resistance. When the contact resistance is larger than 800 kΩ, the emission current from carbon nanotube tends to be zero and the field emission properties are improved via modulating gate voltage.
Keywords： carbon nanotube array with parallel grid floated sphere field enhancement factor contact resistance