Numerical simulations on field emission properties of an open single-walled carbon nanotube with radius r = 1 nm have been carried out. Using finite element method, we have calculated the local electric field F_loc and field enhancement factor γ distribution over the surface of the open CNT. From these calculations, we plot theoretical current-voltage characteristics and assess effective field characteristics for CNT with wall thickness w = 0.2 nm and height h = {3, 11, 101, 1001} nm. It was revealed that the maximum emission current did not change when applied field at the top of the CNT corresponds to the scaled barrier field f = 0.45. Obtained values of effective emission area are in good agreement with surface area, which has the highest field enhancement factor. In addition, we have plotted a “map” of maximum field enhancement factor γ_a for open CNTs with various wall thickness - w ϵ [0.1; 0.9] nm and heights h ϵ [11; 1001] nm. It was shown that maximum field enhancement factor is a nonlinear function of h/r and h/w ratios.

 已经对半径r = 1 nm的开放单壁碳纳米管的场发射特性进行了数值模拟。使用有限元方法，我们计算了开放CNT表面上的局部电场F _loc和场增强因子γ分布。根据这些计算，我们绘制理论电流-电压特性并评估壁厚w  = 0.2 nm 和高度h  = {3, 11, 101, 1001} nm 的CNT 的有效场特性。结果表明，当在 CNT 顶部施加的场对应于缩放的势垒场f时，最大发射电流没有变化 = 0.45。获得的有效发射面积值与具有最高场增强因子的表面积非常吻合。此外，我们还绘制了具有不同壁厚的开放 CNT的最大场增强因子γ _a的“图” - w ϵ [0.1; 0.9] nm 和高度h ϵ [11; 1001] 纳米。结果表明，最大场增强因子是h/r和h/w比率的非线性函数。