碳纳米管薄膜的场发射特性研究*

碳纳米管薄膜是一种能应用于场发射平面显示器等器件中的新型冷阴极材料。该文用Ni作为催化剂，采用催化热解法在硅片上制备了多壁碳纳米管薄膜场发射阴极，反应气体为乙炔、氢气和氮气。用SEM和TEM分析了其结构，证明了碳纳米管的直径在50~70 nm间。进而采用二极管结构，在优于10-4Pa的真空度下，测试了它的场发射特性，理论分析表明碳纳米管薄膜的场发射实际上来源于突出于薄膜表面的部分碳纳米管顶端。该阴极的开启电场为8 V/μm；在11 V/μm时测试到了最大的发射电流密度2 mA/cm2，满足场发射平面显示器的要求。

In this paper, Nanotubes films are grown by thermal chemical vapour deposition on silicon substrates with nickel as a catalyst particle. The SEM, TEM has been used in order to determine the structure of the films, which show that the diameters of nanotubes are 50~70 nm. characterization has been measured on the CNT-anode setup room temperature and in a vacuum chamber. The Fowler-Nordheim plot shows a good linear fit, indicating that the emission current only comes from the protruded nanotubes. Threshold field strength of this nanotubes film is about 8 V/μm for an emission current of 1 μA, and the most field emission current densities of more than 2 mA/cm2 are measured for 11 V/μm. In addition, the bright light spot can be observed, while emitted electron bombardment fluorescent screen.