A method of manufacturing a carbon nanotube field emitter for field emission displays by electrophoresis is disclosed. The method of manufacturing involves: first, loading an electrode plate and the field emitter substrate, which are spaced apart from one another, into an electrophoresis bath containing a carbon nanotube suspension for the electrophoresis; second, applying a predetermined bias voltage from a power supply between the electrode plate and the cathodes of the field emitter substrate to deposit, at room temperature, carbon nanotube particles on the surface of the electrodes exposed through the holes of the dielectric film; and third, drawing the field emitter substrate, on which the carbon nanotube particles have been deposited, out of the electrophoresis bath, and heating the field emitter substrate with carbon nanotube tips at a predetermined temperature. An efficient low-temperature process, incorporating low cost carbon nanotube particles, provides for a lower manufacturing cost.
A process for fabricating a field emitter electrode includes: impregnating a cathode and anode in an electrolyte containing carbon nanotubes dispersed therein and applying a predetermined voltage to the cathode and anode so as to deposit carbon nanotubes on a substrate provided on the anode; recovering the substrate and applying a conductive polymer onto the surface of the substrate having carbon nanotubes deposited thereon; and heat treating the conductive polymer having carbon nanotubes deposited thereon, so as to completely cure it.
A manufacturing method for an electron-emitting source of triode structure, including forming a cathode layer on a substrate, forming a dielectric layer on the cathode layer, and positioning an opening in the dielectric layer to expose the cathode layer, wherein the opening has a surrounding region, forming a gate layer on the dielectric layer, except on the surrounding region, forming a hydrophilic layer in the opening, forming a hydrophobic layer on the gate layer and the surrounding region, wherein the hydrophobic layer contacts the ends of the hydrophilic layer, dispersing a carbon nanotube solution on the hydrophilic layer using ink jet printing, executing a thermal process step, and removing the hydrophobic layer. According to this method, carbon nanotubes are deposited over a large area in the gate hole.
A method of fabricating a field emission device cathode using electrophoretic deposition of carbon nanotubes in which a separate step of depositing a binder material onto a substrate, is performed prior to carbon nanotube particle deposition. First, a binder layer is deposited on a substrate from a solution containing a binder material. The substrate having the binder material deposited thereon is then transferred into a carbon nanotube suspension bath allowing for coating of the carbon nanotube particles onto the substrate. Thermal processing of the coating transforms the binder layer properties which provides for the adhesion of the carbon nanotube particles to the binder material.
The present invention is directed toward field effect transistors (FETs) and thin film transistors (TFTs) comprising carbon nanotubes (CNTs) and to methods of making such devices using solution-based processing techniques, wherein the CNTs within such devices have been fractionated so as to be concentrated in semiconducting CNTs. Additionally, the relatively low-temperature solution-based processing achievable with the methods of the present invention permit the use of plastics in the fabricated devices.
