The Study Of The Preparation And Properties Of Carbon Nanotube Field-emission Cathode

Carbon nanotube is a seamless hollow tube with a diameter of nanometer order,which is formed by curling a layer or a plurality of layers of graphite sheets according to a certain spiral angle.Because of its unique structure,excellent properties and wide potential applications,carbon nanotubes have attracted wide attention from the scientific and technological circles.Carbon nanotubes because of its own with nanoscale tip and high aspect ratio and other excellent characteristics,which has great advantage in the production of material as field emission cathode,field emission cathode materials is the most potential.This paper first introduces the research status at home and abroad of the cathode carbon nanotube field emission,then introduces carbon nanotubes,including the classification,the performance of carbon nanotubes,preparation and application,and makes a detailed research on the field emission theory of carbon nanotube field emission devices and field emission devices in detail introduction.Then,through the use of screen printing method and spin coating prepared carbon nanotube films,on the formulation and manufacturing process were studied,and the carbon nanotube film preparation of field emission performance test.Finally,by using the comprehensive method of heat treatment and late brush treatment method for processing carbon nanotube films,to improve the field emission performance.According to the field emission performance test and scanning electron microscope analysis,the following results are obtained:1.Carbon nanotube films obtained by the screen printing method,through field emission performance testing,found that the threshold voltage is 2.22 V/μm,when the electric field strength is 4.44 V/μm,the field emission current density is 300μA/cm~2.2.The carbon nanotube cathode film was prepared by spin coating method under the condition of the same size.The turn-on voltage was reduced from 2.22 V/μm to 1.90 V/μm,and the current density increased from A/cm~2 to m at 450 μA/cm~2 at the electric field intensity of 4.4 V/μm.3.Preparation of carbon nanotube films by spin coating method,and the carbon nanotube film by heat treatment and brush treatment,results showed that after postprocessing of carbon nanotube thin film cathode current density under the same conditions(4.4 V/μm)increased from 450 μA/cm~2 to 1000 μA/cm~2,and the field emission test in brightness and the density were greatly improved.