Claims
- 1. An electron-emissive film comprising a surface defining a plurality of emissive clusters uniformly distributed over the surface, wherein each of the plurality of emissive clusters is generally star-shaped, wherein each of the plurality of emissive clusters includes a plurality of dendrites extending from a central point, and wherein each of the plurality of dendrites includes a ridge having a radius of curvature that is less than 10 nm.
- 2. The electron-emissive film of claim 1, wherein the ridge of each of the plurality of dendrites has a radius of curvature that is less than 2 nm.
- 3. The electron-emissive film of claim 1, wherein the ridge of each of the plurality of dendrites is oriented in a direction away from a plane defined by the electron-emissive film.
- 4. The electron-emissive film of claim 1, wherein each of the plurality of dendrites has a length within a range of 50-400 nm.
- 5. The electron-emissive film of claim 1, wherein each of the plurality of dendrites has a height of about 100 nm.
- 6. The electron-emissive film of claim 1, wherein the plurality of dendrites are oriented to cause electric field enhancement at the plurality of dendrites.
- 7. The electron-emissive film of claim 1, wherein the plurality of dendrites are comprised of carbon.
- 8. The electron-emissive film of claim 7, wherein each of the plurality of dendrites is comprised of a plurality of graphene sheets having a lattice spacing within a range of 0.342-0.350 nanometers.
- 9. The electron-emissive film of claim 7, wherein an overall composition of the electron-emissive film comprises about 80% graphitic nanocrystallites and about 20% amorphous carbon.
- 10. The electron-emissive film of claim 7, further comprising an emission site density greater than 1.times.10.sup.6 sites/cm.sup.2 at an average electric field of 20 V/.mu.m.
- 11. The electron-emissive film of claim 7, wherein each of the plurality of dendrites comprises a ridge having a radius of curvature within a range of 1-2 nm.
- 12. The electron-emissive film of claim 7, wherein each of the plurality of emissive clusters is generally star-shaped.
- 13. The electron-emissive film of claim 7, wherein the ridge of each of the plurality of dendrites is oriented in a direction away from a plane defined by the electron-emissive film.
- 14. The electron-emissive film of claim 7, wherein each of the plurality of dendrites has a length within a range of 50-400 nm.
- 15. The electron-emissive film of claim 7, wherein each of the plurality of dendrites has a height of about 100 nm.
- 16. The electron-emissive film of claim 7, wherein the plurality of dendrites are oriented to cause electric field enhancement at the plurality of dendrites.
- 17. A field emission device comprising:
- a cathode having an electron-emissive film, the electron-emissive film having a surface defining a plurality of emissive clusters uniformly distributed over the surface, wherein each of the plurality of emissive clusters is generally star-shaped, wherein each of the plurality of emissive clusters includes a plurality of dendrites extending from a central point, and wherein each of the plurality of dendrites includes a ridge, the ridge having a radius of curvature that is less than 10 nm; and
- an anode disposed to receive electrons emitted from the electron-emissive film of the cathode.
RELATED APPLICATION
Related subject matter is disclosed in patent application Ser. No. 08/720,512, filed Sep. 30, 1996, entitled "Electron Emissive Film and Method", which is hereby incorporated by reference.
US Referenced Citations (5)
Non-Patent Literature Citations (2)
Entry |
"A Carbon Nanotube Field-Emissiion Electron Source" by Walt A. de Heer, A. Chatelain, D. Ugarte; Science, vol. 270, Nov. 17, 1995, pp. 1179-1180. |
"Unraveling Nanotubes: Field Emission from an Atomic Wire" by A.G. Rinzler, et al; Science, vol. 269, Sep. 15, 1995, pp. 1550-1553. |