Field emission characteristics of carbon nanotubes deposited on various metal cathodes

We evaporate various highly conductive metal materials on the glass as the cathodes, and then deposit multi-walled carbon nanotubes (MWCNTs) onto cathodes by spraying technique. Moreover, by the deposition of MgO and CsI on CNTs to further enhance the field emission current density of the components. The structure of the electron emitting source is glass/cathode/MWCNTs/MgO/CsI. In the present study, three different metals, Cu, Al, and Ag, are evaporated on glass, in addition to silver paint is spin-coated on glass. Experimental results reveal that field emission capability of the emitter depends on the cathode materials we use. An optimal current density of 62.5 mA/cm² at 1.46 V/μm is achieved when the silver paint is used as the cathode.