Synthesis Of Multi-Walled Carbon Nanotube Films And Their Field Emission Properties

As a great discovery after C60 in the field of carbon materials,carbon nanotube is a concentric hollow tube which is curled by one graphite sheet or more. Because of peculiar structure, physical and chemical properties,carbon nanotube has attracted much attention in variety of fields and is considered to be the nanomaterial which has most theoretical research and application value. Carbon nanotube has high surface area, high mechanical strength, chemical stability and excellent electrical conductivity in the axial to transmit electrons. Nano-scale points and defects in walls form good electron transmitting terminal. Among field emission cathode materials.carbon nanotube has low turn-on voltage and high field emission current density and so on. Consequently carbon nanotube becomes the most potential field emission cathode materials instead of diamond and Si. At the beginning,this paper describes carbon nanotubes' discovery, structure, basic properties, preparation and related applications, specifically introduces the application in field emission cathode materials in detail. Then direct growth on substrate method and transplantation method are studied to fabricate field emission cathode. Meanwhile.the deep research into optical characteristics and electrical characteristics are carried out. Finally, lots of deficiencies and some possible measures to improve field emission property have been related which will be the focus of future work.Chapterâ… IntroductionIn this chapter, the discovery of carbon nanotubes is reviewed. Then the structure characteristics, categories and performance characteristics of carbon nanotubes are briefly introduced. Base on these,some applications of carbon nanotubes are investigated in detail, including storage energy, nano-composite materials, biomedicine engineering and field emission materials. Then this text especially focuses on the field emission application. Chapter II Preparations of Carbon Nanotubes and Related Production of Thin Film Field Emission CathodeIn this chapter, the technologies and conditions for the growth of carbon nanotubes are discussed for different methods, which include the chemical vapor deposition method, the arc discharge method and the laser ablation method. In this text we mainly focuses on carbon nanotubes'preparation using chemical vapor deposition method and the preparation of the catalyst. Then based on this, this chapter investigates the production process of the thin film field emission cathode further.Chapter III The Research of Carbon Nanotube Field Emission FilmThis chapter presents two types of field emission display device whose cathode materialls are carbon nanotube films prepared by chemical vapor deposition method. We test the field emission properties of the two types of device using diode structures whose cathode films are produced by direct growth on substrate method and screen-printing process respectively. Experimental results show that, the field emission cathode film grown on substrate has lower turn-on voltage and higher brightness so that it is considered as excellent field emission cathode. Meanwhile. the field emission cathode film produced by screen-printing process has its own advantages.such as lower cost, mature technology,easy to obtain large area manufacture. Finally based the research above,we analyze the problems which the carbon nanotubes cathodes of field emission display still have, and make some prospects in these aspects.