Electron emission apparatus and method for making the same

An electron emission apparatus comprising:

• an insulating substrate;
• a plurality of first electrodes and a plurality of second electrodes located on the insulating substrate, wherein the plurality of first electrodes and the plurality of second electrodes are spaced from and parallel to each other;
• a plurality of third electrodes and a plurality of fourth electrodes located on the insulating substrate, wherein the plurality of third electrodes and the plurality of fourth electrodes are spaced from and parallel to each other,
• wherein the plurality of first electrodes and the plurality of second electrodes are insulated from and intersect the plurality of third electrodes and the plurality of fourth electrodes, thus defining a plurality of grids;
• each of the plurality of grids comprises an electron emission unit comprising at least one carbon nanotube wire, the at least one carbon nanotube wire comprises:
• a first end electrically connected with one of the plurality of first electrodes or one of the plurality of second electrodes;
• a second end electrically connected with one of the plurality of third electrodes or one of the plurality of fourth electrodes, and
• two electron emission ends defining a gap, each electron emission end comprises a plurality of electron emission tips, the plurality of electron emission tips are cone-shaped, each of the plurality of electron emission tips comprises a plurality of parallel carbon nanotubes combined with each other by van der Waals attractive force comprising a single carbon nanotube extending through the plurality of parallel carbon nanotubes, the single carbon nanotube forms a tip of each of the cone-shaped electron emission tips.

An electron emission apparatus comprising:

• an insulating substrate having a surface;
• a plurality of first electrodes and a plurality of second electrodes located on the insulating substrate, wherein the plurality of first electrodes and the plurality of second electrodes are spaced and parallel to each other;
• a plurality of third electrodes and a plurality of fourth electrodes located on the insulating substrate, wherein the plurality of third electrodes and the plurality of fourth electrodes are spaced and parallel to each other;
• wherein the plurality of first electrodes and the plurality of second electrodes are insulated from and intersect the plurality of third electrodes and the plurality of fourth electrodes, thus defining a plurality of grids;
• each of the plurality of grids comprises an electron emission unit comprising a plurality of carbon nanotube wires, the plurality of carbon nanotube wires are spaced from each other, each of the plurality of carbon nanotube wires comprises a plurality of carbon nanotube segments joined end-to-end by van der Waals attractive force, each of the plurality of carbon nanotube segments comprises a plurality of carbon nanotubes substantially parallel with each other and combined with each other by van der Waals attractive force therebetween, each of the plurality of carbon nanotube wires has:
• a first end electrically connected with one of the plurality of first electrodes or one of the plurality of second electrodes,
• a second end electrically connected with one of the plurality of third electrodes or one of the plurality of fourth electrodes, and
• two electron emission ends defining a gap, a portion of the plurality of carbon nanotube segments defines a plurality of cone-shaped electron emission tips at each of the two electron emission ends, each of the plurality of electron emission tips comprises a plurality of carbon nanotubes combined with each other by van der Waals attractive force.