采用半导体光刻技术在硅衬底上获得图形化掩膜,然后用热化学气相淀积(T-CVD)的方法制备了图形化的碳纳米管线阵列,用扫描电镜和拉曼光谱仪对碳纳米管进行了表征。研究了图形化碳纳米管线阵列的场发射特性,并与无图形化处理的碳纳米管薄膜样品的场发射特性进行了比较。当发射电流密度达到10 μA/cm2时,无图形化处理的碳纳米管薄膜、10 μm碳纳米管线阵列以及2 μm碳纳米管线阵列样品的开启电场分别为3 V/μm、2.1 V/μm和1.7 V/μm;而当电场强度达3.67 V/μm时,相应的电流密度分别为2.57 mA/cm2、4.65 mA/cm2和7.87 mA/cm2。 实验结果表明,图形化处理后的碳纳米管作为场发射体,其场发射特性得到了明显的改善。对改善的原因进行了分析和讨论。

Using standard photolithography,patterned carbon nanotube line arrays were fabricated on silicon substrates by thermal chemical vapor deposition.Scanning electron microscopy and Raman spectroscopy were used to characterize the structure of the carbon nanotubes.The carbon nanotubes were very uniform and about 50 nm in diameter and 2 μm in length.The Raman spectrum showed that the carbon nanotubes were multi-walled carbon nanotubes.Field emission characteristics of the samples were characterized.It was found that the non-patterned carbon nanotube films,10 μm and 2 μm size carbon nanotube line arrays field emission characteristics were gradually improved with turn-on field of 3 V/μm,2.1 V/μm,1.7 V/μm and emission current density at applied electric field 3.67 V/m were 2.57 mA/cm2,4.65 mA/cm2,7.87 mA/cm2,respectively.The reasons may attribute to the field-screening effect and edge effect by analyzing the experimental results.