Development of Carbon Nanotube Based Cold Electron Sources with Low Energy Consumption and High Emission Current

碳纳米管（CNT）生产的发展和CNT场发射体的基本性能的阐明进行的目的是显示碳纳米管作为场发射电子源的适用性。本研究的主要成果如下：1.碳纳米管的生长条件找到了制备高纯度多壁碳纳米管（MWCNTs）和纳米纤维的生长条件，并找到了合成单壁碳纳米管（SWCNTs）的高效催化剂Rh-Pt.清洁碳纳米管的电子发射和吸附物的影响碳纳米管表面清洁时，碳五边形优先产生场发射，而碳纳米管尖端有气体分子时，吸附物会增强场发射.环境气体对碳纳米管场发射的影响在所研究的各种环境中，氧气、甲烷和一氧化碳是对碳纳米管电子发射最有害的气体. CNT-电子源的能量分布、亮度和角电流密度来自一个MWNT的电子能量分布具有330 meV的宽度。发射电流密度和角电流密度分别为10^8A/cm^2和10^<-7>A/sr，<10>在100 kV加速时亮度为10^ A/cm^2 sr.超高亮度碳纳米管光源的实验研究用纳米碳纤维制作的超高亮度碳纳米管光源在30 kV直流驱动下显示出10^6 cd/m^2的亮度，比以前制作的高出10倍以上。

Development of carbon nanotube (CNT) production and elucidation of fundamental properties of CNT field emitters were carried out with the aim of showing applicability of CNTs as field emission electron sources. Followings are the main achievement of the present study.1. Growth conditions of CNTsGrowth conditions for obtaining high purity multiwall CNTs (MWCNTs) and special MWCNTs called nanografibers were found. Efficient catalysts such as Rh-Pt for synthesizing single-wall CNTs (SWCNTs) were also found.2. Electron emission from clean MWNTs and the effects of adsorbatesField emission occurred preferentially from carbon pentagons when the CNT surfaces were clean, while the enhanced emission was observed through adsorbates when the gas molecules were on the CNT tip.3. Effect of ambient gases on the CNT field emittersAmong various ambient studied, oxygen, methane and carbon monoxide were the most hazardous gases degrading the electron emission from CNTs.4. Energy distribution, brightness, and angular current density of CNT-electron sourcesAn electron energy distribution from one MWNT had a width of 330 meV. Emission current density and angular current density were respectively 10^8A/cm^2 and 10^<-7>A/sr, giving 10^<10>A/cm^2 sr as brightness at 100 kV acceleration.5. Experimental fabrication of ultra-high luminance CNT light sourcesThe fabricated ultra-high luminance light-sources by using nanografibers showed 10^6 cd/m^2 at 30kV dc-driving, the brightness being more than 10 times higher than that manufactured previously.