| The FED possess many distinct properties, such as thin panel thickness, excellent image quality, wide viewing angle, quick response, easy to implement digital control, free from the terrestrial magnetic effect etc. As a novel flat-panel display, the FED has been regarded as a promising competitor to the CRT. Carbon nanotube (CNT) is prefect field emission electron source due to their high aspect ratio, well chemical stability and higher melting point. CNTs film is easy to be prepared using screen-printed or coated method which is fit for large area display. CNTs film in this way has low cost and suitability for mass production. However, its field emission performance, Stability and uniformity need further improvement. The synthesis CNTs with certain function is hard to realize for its high cost and technical difficulty. The modification of CNTs surface in suitable way is a shortcut to improve field emission function.In this paper, we mainly discuss how to improve field emission function of multi-walled carbon nano-tubes (MWCNTs) film using screen-printed or coated method. Main conclusion and innovative results are presented as follow:(1) The MWCNTs film successfully is synthesised by CVD method. We studied the field emission performance of diode and triode structure prepared by screen-printed method. The result shows that triode structure excels diode structure at function. We also found that the coated method is better than screen-printed in field emission performance, whereas the current is not enough to be stable.(2) The temperature dependence of the resistance and field emission are investigated and show that the resistance of MWCNTs film becomes smaller and emission performance is better with temperature increment. This result can be attributed to somefactors, such as the work function,βfactor distribution broadening, and transportcharacteristics of electrons at interface of Ag/MWCNTs as well as local hyperthermia. Thus the temperature effect needs to be considered in design of CNTs-FED.(3) The surface treatment of screen-printed MWCNTs emitters using a 248nm (KrF) excimer laser are investigated. The field emission characteristics of MWCNTs are measured following laser irradiation. The results show that the turn-on voltage and the current are highly dependent on the value of the laser fluence. The laser treatment are able to improve the field emission characteristics of MWCNTs, however electron emission are impeded when the energy is higher than 165mJ. This result can be interpreted by photo ablation and thermal ablation mechanisms. The laser treatment is novel and easy to carry out in modification of CNTs film. It provides a precise degree of control over the treatment process which is seldom found.(4) The conductivity of MWCNTs film is increased by doping nickel powders.The field emission performance is improved but not obviously. Coating of MWCNTs was carried out by Ti atom/cluster from chemical reduction. This method results in poor emission performance due to organic matter and other impurity.(5) The field emission performance and conductivity are obviously improved after MWCNTs film deposited a thin layer of titanium. The turn-on voltage evidently decreases. The current increase distinctly and has long time stability. This way improve effectively field emission performance and produce no impurity. It also has low cost and suit for mass production.(6) Emitted current distribution and electron trajectories of individual pixel with the planar gate structure are studied by numerical simulation method. A greater slope angle of the gate-cathode groove enhances emission ability of the cathode, while influences electron trajectories and decreases the display efficiency. 45°is a better choice balanced the two factors. The display quality is gravely affected by the anode -cathode distance.
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