Theory of Carbon Nanotube (CNT)-Based Electron Field Emitters.
Theory of Carbon Nanotube (CNT)-Based Electron Field Emitters.
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DOI：
10.3390/nano3030393
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发表时间：
2013-07-17
期刊：
影响因子：
--
通讯作者：
Eletskii AV
中科院分区：
文献类型：
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作者：
Bocharov GS;Eletskii AV
综述了与基于碳纳米管的电子场发射器的开发和操作相关的理论问题。考虑了碳纳米管 (CNT) 独特发射特性背后的电子场发射的物理方面。分析了影响碳纳米管阴极发射特性的物理效应和现象。特别关注的效应包括：考虑到尖端形状、纳米管垂直方向的偏差以及电场引起的排列，碳纳米管尖端附近的电场放大；相邻纳米管的电场屏蔽；构成阴极的各个碳纳米管的参数的统计分布；热效应导致纳米管在发射过程中降解。同时考虑上述影响，可以根据最大可达发射电流密度开发 CNT 阵列的优化程序。根据该过程，阵列中的最佳管间距离取决于所施加的外部电压的区域。根据最近进行的实验，已经预测并分析了阵列中纳米管的自错位现象。分析了基于 CNT 的电子场发射器的退化机制，其中包括残留气体分子的电子碰撞电离所形成的离子对发射器的轰击。
Theoretical problems arising in connection with development and operation of electron field emitters on the basis of carbon nanotubes are reviewed. The physical aspects of electron field emission that underlie the unique emission properties of carbon nanotubes (CNTs) are considered. Physical effects and phenomena affecting the emission characteristics of CNT cathodes are analyzed. Effects given particular attention include: the electric field amplification near a CNT tip with taking into account the shape of the tip, the deviation from the vertical orientation of nanotubes and electrical field-induced alignment of those; electric field screening by neighboring nanotubes; statistical spread of the parameters of the individual CNTs comprising the cathode; the thermal effects resulting in degradation of nanotubes during emission. Simultaneous consideration of the above-listed effects permitted the development of the optimization procedure for CNT array in terms of the maximum reachable emission current density. In accordance with this procedure, the optimum inter-tube distance in the array depends on the region of the external voltage applied. The phenomenon of self-misalignment of nanotubes in an array has been predicted and analyzed in terms of the recent experiments performed. A mechanism of degradation of CNT-based electron field emitters has been analyzed consisting of the bombardment of the emitters by ions formed as a result of electron impact ionization of the residual gas molecules.