【摘要】 研究了单壁纳米碳管(SWNTs)、双壁纳米碳管(DWNTs)和多壁纳米碳管(MWNTs)在不同真空度下的场发射性能。在超高真空条件下(2.0×10-7Pa),以上三种材料均表现出良好的稳定性;而在高真空条件下(1.0×10-4Pa),三种材料的场发射稳定性有不同程度的下降。通过控制系统真空度在2.0×10-7Pa～1.3×10-3Pa范围内逐渐变化,考察了真空度对纳米碳管场发射性能的影响及其机制,提出适合于SWNTs、DWNTs和MWNTs场发射性能测试和应用的真空度下限分别为6.0×10-5Pa、1.0×10-4Pa和5.7×10-4Pa。更多还原

【Abstract】 Highquality singlewalled carbon nanotubes (SWNTs), doublewalled carbon nanotubes (DWNTs), and multiwalled carbon nanotubes (MWNTs) with a mean diameter of 6?nm were employed for the measurements of their field emission performance in ultrahigh vacuum conditions (UHV, 2.0×10-7?Pa) and high vacuum (HV, 1.0×10-4?Pa), respectively. It was found that all the carbon nanotubes (CNTs) showed good field emission stability in UHV, but the stability of SWNTs and DWNTs deteriorated remarkably in HV, while the MWNTs remained stable. On the other hand, it was found that increasing the working pressure within certain limits was in favor of the emission current increase of CNTs. By cycling the working pressure between 2.0×10-7?Pa and 1.3×10-3?Pa, lower vacuum limits of 6.0×10-5?Pa, 1.0×10-4?Pa and 5.7×10-4?Pa were proposed for the measurements and applications of SWNT, DWNT and MWNT field emitters, respectively.更多还原