Carbon Nanotube Field Emission Properties

Carbon nanotubes (CNTs) with most excellent field emission performance have attracted much attention in the scientific field and have been studied both extensively and in deepth. However, despite early rapid progress, much fundamental work is still lacking. In this thesis, different fabrication methods of CNTs films are presented and the effects on the performance of CNTs are investigated. The primary contents are as follows.1. CNTs, nano-TiO₂ dispersant, Ag electric agent and PVB paste are formed into films and then heated to 400℃ to produce a field emission cathode. The field emission measurements show that this method has high emission field stability and high field emission current density. Optimum field emission properties were obtained by selecting suitable CNTs from which to form the field emission cathode. The electric fields for extracting 10 μA/cm² and 1mA/cm² current densities are found to be approximately 0. 45 V/μm and 0. 72V/μm respectively.2. A novel method of fasbrication of the field emission cathode films of CNTs by pulsed-laser deposition treatment is introduced. The electric fields required for extracting 10μA/cm² and lmA/cm² current densities from the afore-mentioned field emissionh cathode are found to be approximately 2. 69 V/μm and 5. 09V/μm respectively. Furthermore, the emission current density can approach 15. 41mA/cm² with an electric field of 9. 00 V/μm. This new method of fabrication of field emission cathode has never been reported in the literature.3. Fabrication of the field emission CNT film cathode by pulsed-laser...