取向碳纳米管膜的大面积制备及其场发射性能的研究

Synthesis and Field Emission Study of Large-scaled Aligned Carbon Nanotube Films

利用热丝增强化学气相沉积法 ,在镀Ni的Si基片上成功地生长大面积取向碳纳米管膜 ,并研究了其场发射性质。研究表明 ,碳纳米管膜的场发射Fowler Nordheim曲线上存在一转折点Es(“饱和”场强 ) ,低场区域 (E <Es)的F N曲线斜率明显高于高场 (E >Es)区域。实验证实 ,低场区域的场放大系数 β与极间距d成正比 ,Es 与极间距d成反比 ,它们可用双区域场模型唯像地解释。讨论了高场区域场发射电流“饱和”(变化趋缓 )

Large-scaled highly oriented carbon nanotube films on Si substrate with Ni as a catalyst were synthesized by hot-filament-enhanced CVD and field-emission properties of the films were studied.It has been discovered that there is a knee-point E s on Fowler-Nordheim curves of the nanotube films,the slope of F-N curve in the low field region is much higher than that in the high field region.The field-enhancement factor β is proportional to the distance d between the anode and the cathode,and E s is an inverse measure of the distance d. Both of them can be phenomenally interpreted by the two-region field-emission model.The possible mechanisms for the saturation of emitter current on high field region have been discussed.