电泳淀积图形化碳纳米管场发射阴极及其场发射特性研究

Electrophoretic Deposition and Field Emission Characteristics of Patterned Carbon Nanotube Cathode

基于电泳和半导体工艺,制备了图形化的碳纳米管场发射阴极。用较高的电场激活碳纳米管薄膜,使得碳纳米管的场发射特性有了很大的改善,讨论了这一激活过程的物理机制。研究表明,这一激活过程可能的物理机制一方面是由于碳纳米管薄膜表面形貌发生了变化,增大了碳纳米管的场增强因子;另一方面是由于碳纳米管表面吸附的气体脱附,降低了碳纳米管的表面功函数。电场激活处理后,碳纳米管薄膜的开启电场为2.1 V/μm,应用电场为6 V/μm时,电流密度达到1.19mA/cm2。该图形化的碳纳米管场发射阴极可以应用到高分辨率场发射显示器。

Patterened carbon nanotube（CNTs） cathode has been successfully fabricated by combining electrophoresis and by integrated circuit（IC） technology. The high voltage activation considerably improves the field emission characteristics of the CNT cathode, including an onset electric field of 2.1 V/μm and a current density of 1.19 mA/cm^2 at an electric field of about 6 V/μm. Two physical reasons account for the improvements. One is that the activation favorably modifies the surface morphology of CNFs films and increases the enhancement factor, the other is that field desorption of gases from CNFs walls lowers the surface work function.