摘要
研究了定向生长的多壁碳纳米管薄膜场致发射的距离敏感特性,以改进现有场发射传感器中硅及金属针尖的性能。化学气相沉积方法制备的多壁碳纳米管薄膜表现出良好的尖端放电特性,其开启电场可至1.42 V/μm,阈值电场可至2.22 V/μm,通过计算得到的尖端电场增强因子可至4 034以上。随着发射间距的增加,场致发射电流非线性地降低,发射电流对发射间距的最大变化率为0.018 8μA/μm。通过拟合分析发现,场致发射电流随发射间距的变化基本符合Fow ler-N ordhe im关系,该特性可作为碳纳米管场致发射传感器的基本原理用于位移的检测。
Carbon nanotubes （CNTs） were used to improve the performance and lifetime of traditional field emission sensors, instead of existing emission emitters such as silicon and metal tips. Well-aligned multi-wall carbon nanotube films synthesized by chemical vapor deposition showed perfect electron emission properties with a turn-on filed of 1.42 V/μm, a threshold field of 2. 22 V/μm and an enhancement factor of more than 4 034. The field emission I d curves indicate that with increasing inter electrode distance, the emission current decreases non-linearly, with the largest slope as large as 0. 018 8 btA/btm. The experimental and analytical results were contrasted to analyze the relationship between the emission current and the inter-electrode distance using Fowler Nordheim theory. Fowler-Nordheim theory is shown to be suitable for analyzing the I-d relationship of CNT films and for designing CNT-based displacement sensors.
出处
《清华大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
2006年第11期1876-1879,共4页
Journal of Tsinghua University(Science and Technology)
基金
国家自然科学基金资助项目(50375083)
高等学校博士学科点专项科研基金资助项目(20040003065)
关键词
微机电系统
传感器
场致发射
碳纳米管
microelectromechanical system （MEMS）
sensor
field emission
carbon nanotube
