Field Emission of Electrons from Carbon Nanotubes with Extremely Sharp Tips and Its Application to Electron Sources

碳纳米管可能有无物理和化学性质，适用于现场发射器。在本研究中，碳纳米管的现场发射的基本特性是经提炼的，基于纳米管的现场发射显示设备是实验性制造的，其性能也是测试的。由场发射显微镜（FEM）研究的碳纳米管中的电子发射，来自各种碳纳米管的场发射，例如，多层纳米管（MWNT）、纳米纤维（NGF）和单壁纳米管（SWNT）已被调查，目前使用FEM设备构建。在纳米管中研究过、氧化化的MWNTs，具有开放尖端展示了最优秀的发射特性，以及净化的SWNTs和NGF是下一个好发射器。碳纳米管薄膜中碳纳米管的电子发射在阴极上扩散时，纳米管阴极和网格之间的间隙为1毫米，网格电压为750伏，当前密度为2.5 mA/cm的D12的D1为NGF，接近0.1 mA/cm的D12的D1为MWNT和SWNTs. 3。纳米管发射器生命周期的环境气体的影响MWNT发射器的生命测试表明，氧气是纳米管发射器中最危险的气体。纳米管基场发射显示元件及其性能阴极射线管（CRT）照明元件是用纳米管场发射器替换常规热离子阴极制造的。稳定的电子发射，高发射电流在低电场（~ 10 mA/cm，D12，D1，1.5 V/μm），发射器的寿命长。

Carbon nanotubes possess physical and chemical properties favorable for field emitters. In this study, fundamental properties of field emission from carbon nanotubes are elucidated, and nanotube-based field-emission display devices are experimentally manufactured and their performance is examined.1. Electron Emission from Carbon Nanotubes Studied by Field Emission Microscopy (FEM)Field Emission from a variety, of carbon nanotubes, e.g., multiwall nanotube (MWNT), nanografiber (NGF), and single-wall nanotube (SWNT), was investigated by using an FEM apparatus constructed newly. Among the nanotubes studied, oxidized MWNTs with open tips exhibited the most excellent emission properties, and purified SWNTs and NGF were the next good emitters.2. Electron Emission from Films of Carbon Nanotubes Spread on Cathode PlatesWhen the gap between the nanotube cathode and the grid was 1 mm and the grid voltage was 750 V, current density of 2.5 mA/cmィイD12ィエD1 as obtained for NGF, and approximately 0.1 mA/cmィイD12ィエD1 for MWNT and SWNTs.3. Effects of Ambient Gases on Lifetimes of Nanotube EmittersLife tests of MWNT emitters performed under ambient gases of oxygen, water, nitrogen and argon revealed that oxygen was the most hazardous gas for nanotube emitters.4. Fabrication of Nanotube-Base Field Emission Display Elements and Their PerformanceCathode ray tube (CRT) lighting-elements were manufactured by replacing conventional thermionic cathodes with nanotube field emitters. Stable electron emission, high emission current with low electric field (〜10 mA/cmィイD12ィエD1 at 1.5 V/μm), and long life of the emitters were demonstrated.