Electron field emission properties of carbon nanotubes-deposited flexible film

A carbon nanotubes-deposited flexible film was prepared by electrophoretic method. A polyimide film coated with titanium was used as a cathode and a stainless steel plate as an anode, respectively. The two electrodes were placed into a bath with solvent consisting of grinded carbon nanotubes powder, Mg(NO3)2·6H2O and isopropyl alcohol (IPA). Mixed solution was stirred for about 2-4 h to assure the complete dissolution of Mg(NO3)2·6H2O and the dispersion of carbon nanotubes powder, dc electric field was applied to the two electrodes. The anode voltage was about 100 V. After 1-2 min, the carbon nanotubes powders were deposited on the polyimide film coated with titanium. The electron field emission properties of the prepared thin film were tested by a diode assembly. The turn-on field of the flexible film was about 2.96 V/μm. The current density of the flexible film was about 200 μA/cm2 at an electric field of 5.9 V/μm. The morphology and structure of the carbon nanotubes-deposited flexible film were analyzed by scanning electron microscope (SEM) and Raman spectroscopy. The experimental results indicate that this film could be a promising material applicable to cold cathodes.