利用场发射显微镜研究O2对单壁碳纳米管场发射的影响

利用场发射显微镜和四极质谱计研究了充入高纯O2的四极质谱和O2对单壁碳纳米管场发射的影响.单壁碳纳米管经过约1000℃的热处理得到清洁态场发射像后，充入O2，分别测量了O2吸附和脱附后场发射的I V特性.实验观测到在单壁碳纳米管上O2的吸附使场发射电流减小，说明逸出功增加.在10-4Pa的O2压强下对单壁碳纳米管进行约1000℃的热处理，可以产生氧化刻蚀作用，观测到场发射像的变化，并测量了氧化刻蚀产生的I V特性变化. 关键词： 单壁碳纳米管 场发射显微镜 场发射 四极质谱

FEM study on the influence of oxygen on field emission of single-walled carbon nanotubes

Influence of oxygen on the field emission of single walled carbon nanotubes (SWCNTs) was studied using a field emission microscope (FEM) and a quadrupole mass spectrometer. After heat treatment at 1000℃, the field emission of clean SWCNTs occurred. Then oxygen was introduced into the vacuum system and the curves of field emission current versus anode cathode voltage (I V curves) were acquired after oxygen adsorption and desorption, respectively. We have observed that oxygen adsorption on SWCNTs leads to a decrease in field emission current, indicating an increase in the work function. Oxidation etching occurred when the SWCNTs were annealed at about 1000℃ under a pressure of 10-4Pa, and the corresponding changes were observed in both field emission images and I V curves.