Papers by Keyword: Field Emission

Abstract: Diamond film and diamond /Ti film were synthesized by microwave plasma chemical vapor deposition (MWPCVD) method on Si (100). Comparative studies on field emission properties of diamond and diamond /Ti films.The results show that diamond /Ti film has demonstrated large emission currents at much lower threshold voltages. Field emission current density increases rapidly with the increase of electric field and reaches to 1400μA/cm2 at 25 V/μm.

Abstract: With high effective screen-printing process, the field emission display panel with double stripe emitters was fabricated and their good field emission property was also characterized. Using sintered silver slurry with better electric conduction property as material, the cathode electrode including two parts was formed. The top cathode electrode was made up of two silver stripes, which the carbon nanotube material would reside on its surface. The bottom cathode electrode was separated by the cathode separate layer with the top cathode electrode, but the electric-connection would be performed between them through the preformed round holes. Using carbon nanotube as cathode, the field emission display panel with double stripe emitters was demonstrated.

Abstract: The field emission properties of single-wall carbon nanotubes with purity higher than 70%,which were produced by dc arc discharge evaporation of a carbon electrode including 1% Fe catalyst in H2-Ar mixture gas was studied.The single-wall carbon nanotubes that were produced by this method possess high a ‘clean’ surface since the coexisting Fe catalyst nanoparticles can be completely eliminated by a two-step purification process.The field emission properties was verified by measuring the emission current density(J) versus the applied electric field(E), the corresponding Fowler-Nordheim(F-N) plot for the sample.Through looking at the emission photos, the uniformity of field emission is found to be excellent.

Abstract: Field emission property of Ga-doped carbon nanotube (CNT) film has been studied and compared with those of un-doped, N-doped as well as B and N co-doped CNT films. It is found that the Ga-doped CNT film exhibits superior field emission property to the other films. The turn-on field for Ga-doped CNT film is well below 1.0 V/μm, lower than those for un-doped (2.22 V/μm), N-doped (1.1 V/μm), B and N co-doped (4.4 V/μm) CNT films. Its current density reaches 5000 μA/cm² at 2.6 V/μm which is well above those for un-doped (1400 μA/cm²), N-doped (3000 μA/cm²) as well as B and N co-doped (2) CNT films at applied electric field of 5.7 V/μm. First principles calculations were carried out to obtain the binding energy and electronic nature altering of a CNT by Ga doping. It is shown that Ga-doped CNT (8,0) alters from semiconductor to intrinsic metal and a binding energy of 2.7527 eV is obtained. The field emission property can not simply be explained by the defect concentration, but can be understood by significant altering in the local density of states near the Fermi level introduced by dopants.

Abstract: With carbon nanotube as cold cathode, the field emission display based on the improved film-electrode was fabricated. The indium tin oxide film covered on the glass surface was etched to form the film-electrode. For one film-electrode stripe, the left bar electrode and the right bar electrode were formed on the both side of the bottom electrode. The carbon nanotube would be prepared on the bottom electrode surface. The cathode covering layer fabricated with the sintered insulation slurry would cover the left and right bar electrodes. It was confirmed that the emission current could be controlled by the formed electric-field with the improved film-electrode.

Abstract: With printed silver electrode and etched indium tin oxide (ITO) stripe, the double cathode-conducting-layer was developed on the cathode back plane. The lower ITO electrodes were composed of divided ITO film covered on the cathode back plane and the upper silver electrode was formed by the sintered silver slurry. And the cathode insulation layer was used to separate the lower ITO electrodes and the upper silver electrodes. Carbon nanotube used as field emitters, the fabrication research on the field emission display panel was performed. The main function for the double cathode-conducting-layer was to decrease the cathode voltage drop on the upper silver electrodes on the cathode back plane. The sealed small size field emission display panel possessed better image display performance.

Abstract: Using first-principles density-functional theory investigate (5, 5) capped single-walled carbon nanotubes adsorbed at one end by hydrogen molecule with and without an applied electric field. It is found that the structure of carbon nanotubes with hydrogen molecules is stable under field-emission conditions. The induced dipole moments is the direction of the applied electric field，and the LUMO-HOMO energy gaps decrease. These results elucidate that the field-emission properties of carbon nanotubes can be enhanced by the adsorption of hydrogen molecules, and are consistent with the experimental results.

Abstract: Nanomaterials such as 1-dimensional nanowires and nanotubes and 2-dimensional graphene are the promising materials for novel device developments due to their unique physical and chemical properties. For field emission applications, nanomaterials are excellent candidate for an electron source by advantages of their small dimensions and high aspect ratios. In this study, we used GaN nanowires as the nanomaterials synthesized by Vapor-Liquid-Solid method. The field emission devices were then fabricated using the general Si microfabrication techniques. Moreover, the field emission properties of the GaN nanowires were characterized using cold field emission theory. It is demonstrated that the fabrication techniques shown in this study are efficient to fabricate field emission devices using nanomaterials.

Abstract: Carbon fibers (CNFs) were surfacial metallized by electroless deposited with nickel, and their field emission properties were investigated by diode test. The results indicated that the CNFs owned better field emission properties after electroless depositing nickel for 30 min, with nickel metal thickness as 3.25 µm and the volume resistivity down to 1.3510-4 Ω•cm. The morphology and composite of Ni-coated CNFs were characterized by scanning electron microscope (SEM) and X-ray diffractions (XRD), respectively. The results indicated Ni-coated CNFs were amorphous and had better surface. The field emission tests showed when applied voltage was 832V, Ni-coated CNFs appeared bright dots, and the high luminance achieved 988cd/m2 under applied voltage 1456V.

Abstract: With screen-printing method, the diode field emission display panel was fabricated. On the cathode back plane, the cross-like cathode electrode structure was developed for improving the field emission properties of field emission display panel. The prepared carbon nanotubes were utilized to form the electron emission sources, and the necessary cathode potential for the carbon nanotube cathode could be conducted by the indium tin oxide stripe. Seen from the fabrication pattern, the divided indium tin oxide stripe was cross-like, but the fabrication surface for the single carbon nanotube cathode pixel was circular. The whole field emission display panel possessed good field emission characteristics.