碳纳米管/纤维阴极场发射平板显示器研制

探索了从碳纳米管/纳米纤维（CNT/CNF）的制备到CNT/CNF阴极场发射平面显示器(c-FED)封装的工艺流程.用化学气相沉积方法,优化制备条件获得了纯度较高的CNT/CNF;以 CNT/CNF和低压荧光粉为原料,采用丝网印刷工艺制作显示器的阴极和阳极;采用类真空荧光显示器的封装工艺封装了c-FED样管.所研制的c-FED具有优良的场发射性能,较好的均匀性及发光密度,黄色荧光粉的c-FED在电场为 2.7 V/μm时的亮度可达600 cd/m².因该显示器使用普通玻璃作为阴阳极基板,整个工艺流程在大面积和实用化方面有很好的应用潜力.      

单壁碳纳米管及其电学特性研究

制造和提纯了单壁碳纳米管 (SWCNTs) ,用水溶胶体将其竖直地组装在Au薄膜表面 .用此组装技术制造了扫描隧道显微镜 (STM)的针尖 ,成功地观测到了Au晶粒的形貌像和高定向石墨 (HOPG)的原子像 .将单根SWCNT组装在W尖前端 ,置于场发射显微镜 (FEM)系统中 ,观察到了SWCNT开口端的碳原子电子发射像 .测量了站立在Au表面SWCNT的电学特性 .其电子态分布 ,有的呈现半导体特性 ,有的为金属特性 .这种组装技术可用于制造高亮度相干电子源、高分辨场发射显示器、高性能的扫描探针显微镜 (SPM)针尖和组装纳米电子器件等 .     

ZnO纳米线在外加电场下的生长及场发射性能

在外加电场条件下,利用化学气相沉积法制备出了长径比为400:1的四角状ZnO纳米线.利用多功能场发射测试仪对ZnO纳米线进行了场发射特性测试,研究了外加电场对ZnO纳米线生长的影响,讨论了ZnO纳米线在强场下的场发射电流强度饱和现象产生的原因.结果表明:外加电场大大促进了四角状ZnO纳米线在一维方向上的生长,外加电场下制备的ZnO纳米线在电流密度为0.1 mA/cm2的开启场强仅为2.25V/μm,ZnO纳米线在强场下的场发射电流强度饱和现象归因于强场下电子输运速度的饱和.     

Growth mechanism of octahedron-like BaMoO4 microcrystals processed in microwave-hydrothermal: Experimental observations and computational modeling

Octahedron-like BaMoO4 microcrystals were synthesized by the co-precipitation method at room temperature and processed in microwave-hydrothermal at 413 K for different times （from 30 min to 5 h）. These microcrystals were analyzed by X-ray diffraction （XRD）, field-emission gun scanning electron microscopy （FEG-SEM） and transmission electron microscopy （TEM）. XRD patterns showed that this material presents a tetragonal structure without the presence of deleterious phases. FEG-SEM and TEM micrographs revealed that the BaMoO4 microcrystals present an octahedron-like morphology with agglomerate nature and polydisperse particle size distribution. These micrographs also indicated that the microcrystals grow along the [0 01 ] direction. The observed crystallographic planes in these structures were modeled computationally and a crystal growth model was proposed in order to explain the morphological changes as a function of processing time.     

取向和非取向In2O3纳米线的场发射研究

用自制的设备制备了取向和无取向氧化铟纳米线,并研究了In2O3纳米线的场发射性质,发现取向纳米线比非取向纳米线有着更好的场发射特性.取向纳米线的开启和阈值场强明显低于非取向纳米线,这可能是由于取向纳米线之间的场屏蔽效应较弱以及取向纳米线有较多的顶部发射端的缘故.     

一种基于碳管场发射显示器结构分析

用边界元法(BEM)和MonteCarlo方法就一种基于碳纳米管场发射大面积彩色平面型显示器的可行性进行了理论分析,通过模拟跟踪发射电子轨迹,证实设计的显示器结构能够满足高分辨率显示的要求,而且驱动电压低、工艺简单,尤其和日本Cannon公司的M.Okuda等人提出的表面传导型场发射显示器结构相比,其电子传输比有大幅度的提高.     

单颗粒CVD金刚石的场发射

利用改造的扫描电子显微镜(SEM)设备，在SEM腔体中利用钨(W)探针测试了单颗粒金刚石的I-V与场发射特性，结果表明结晶良好的金刚石的I-V特性服从欧姆定律，而孤立的菜花状金刚石颗粒(cauliflower-like diamond)的I-V特性基本符合Pool-Frenkel输运特性.场发射特性表明，结晶良好的金刚石薄膜基本没有场发射，而孤立的菜花状的金刚石颗粒具有一定的场发射.CVD金刚石的场发射过程中，缺陷对电子的输运起主导作用.     

石墨基底上垂直生长碳纳米管为芯的碳锥结构

采用一种改进的化学气相沉积方法，成功地在石墨基底上自组装生长出以碳锥为支撑的、碳纳米管为芯的新型功能材料.该结构的材料可以用作扫描电子显微镜探针和场发射电子显微镜的针尖.利用电子显微镜研究了不同合成条件对该碳纳米管与碳锥结构生长的影响，给出了最优生长条件，并讨论了生长机制. 关键词： 碳锥 碳纳米管 化学气相沉积 场发射     

Electron emission degradation of nano-structured sp^2-bonded amorphous carbon films

The initial field electron emission degradation behaviour of original nano-structured sp^2-bonded amorphous carbon films has been observed, which can be attributed to the increase of the work function of the film in the field emission process analysed using a Fowler-Nordheim plot. The possible reason for the change of work function is suggested to be the desorption of hydrogen from the original hydrogen termination film surface due to field emission current-induced local heating. For the explanation of the emission degradation behaviour of the nano-structured sp2-bonded amorphous carbon film, a cluster model with a series of graphite （0001） basal surfaces has been presented, and the theoretical calculations have been performed to investigate work functions of graphite （0001） surfaces with different hydrogen atom and ion chemisorption sites by using first principles method based on density functional theory-local density approximation.     

具有发展潜力的场发射平板显示器

本文简要介绍了平板显示器的发展趋势;比较了几种平板显示器的性能;对于场发射平板显示器的发展前景进行了展望。