The Research About The Field Emission Properties Of Normal-gated Carbon Nanotube Bundle Array

The traditional field emission tip of metal or semiconductor has lower aspect ratio, inferior field emission performance. Melt and become dull easily at high temperature, thus the useful life is shortened. Basing on the development of modern technology, carbon nanotubes have many kinds of preparation methods , the technology of preparation and purification of carbon nanotubes trend to maturity more and more. Above all, carbon nanotubes is the best choice as field emission cathode material.Because the CNTs have excellent field emission performances, and the field emission display (FED) was considered to be one of the most promising next generation display technologies after Light Emitting Diode (LED). The CNTs bundle can be got easily on experiment. As a result, the CNTs bundle with excellent field emission performance and high-output have become the research hotspots.In this paper, we summarized the developing circumstances about the field emission of CNTs firstly. Basing on the field emission theory of the CNTs, the field emission performances of the single CNT field emission cathode with diode and triode structure, the normal-gated hexagon pitch CNTs array cold cathode field emission displayer (FED), CNTs bundle array and CNTs bundle have been discussed orderly. The affect factors on the field emission performance of each structure and the optimal value of the factors have been obtained and explained also. Lastly, considering the feasibility of technology, the field emission cathode model which is suited to Industrial Applications has been established by comparing the field emission performances of each structure. The results indicated that: normal-gate could enhance the field emission performances of cathode. Normal-gated single CNT and its array possess of high field enhancement factor and emission current density, although the preparations are hard to achieve. By contrast, the preparation of CNTs bundle and CNTs bundle array is easier by large scale, more important, the field emission performances are enhanced critically comparing other emitters and applied sufficiently in practice. Thus, Based on an overall consideration of feasibility of technology and excellent field emission performances, the hexagon pitch CNTs bundle array with normal gate has been established, field emission and technology parameters are analyzed, and providing a theoretical reference in practice.