【摘要】 本文以Maxwell电磁场理论为基础,对金属型单壁碳纳米管场发射阴极尖端附近的电场进行了计算,给出了不同结构单壁碳纳米管尖端附近的电场分布,发现场强沿管的径向及轴向方向随与管尖端距离的增加而迅速下降,说明了碳纳米管产生的激发场为极强的小范围局域场。通过计算不同几何尺寸单壁碳纳米管的场增强因子随其长度、半径的变化曲线,发现单壁碳纳米管的场增强因子数值非常大,并且根据曲线的变化规律可知,越细越长的单壁碳纳米管具有更大的场增强因子,同时也表明了单壁碳纳米管作为场发射阴极具有低的阈值和大的发射电流密度。本文所得结果为单壁碳纳米管做场发射材料提供了理论参考。更多还原

【Abstract】 The electric field near the tip of metallic single-walled carbon nanotubes(SWNTs) is calculated based on Maxwell electromagnetic theory in this paper.On that base the distributions of the electric field near the tip of SWNTs of different geometrical size are illustrated.It is found that along the direction of radius and axis of the nanotube the electric field strength drops sharply with the distance away from the tip increasing,and it is proved that the stimulated electric field from SWNTs is a strong field of limited range.Through calculating the curves of the electric field enhancement factors of SWNTs of different structures according to its length and radium,we find that the value of the electric field enhancement factor is rather high,and from the rules of the curves it is found that the slimmer and longer of the SWNTs,the higher its electric field enhancement factors are.And at the same time,quite low threshold voltage and high field emission electric current density of SWNTs as a field emission cathode are shown.The results of this paper provide a theoretical reference for the SWNTs to be a ideal field emission material.更多还原