AVS 51st International Symposium
    Nanometer-scale Science and Technology Tuesday Sessions
       Session NS-TuP

Paper NS-TuP20
Fabrication and Characterization of Carbon Nano-Cone Electron Emitters

Tuesday, November 16, 2004, 4:00 pm, Room Exhibit Hall B

Session: Poster Session
Presenter: K. He, University of Houston
Authors: K. He, University of Houston
N. Badi, University of Houston
A. Bensaoula, University of Houston
Correspondent: Click to Email
R&D on effective field emitter arrays (FEAs) is now concentrated on nano-structured solid materials because of the significant local increase of the electric field on solid tips with a small radius of curvature. This paper reports on the electron field emission behavior from uncoated and boron nitride coated graphite nano-cones. Since nano-cones emit most of their current into a single narrow beam, it is expected that graphite nano-cones electron emitters will lead to a significant improvement in the performance of high-resolution electron-beam instruments as well as for high power microwave amplifiers. Fresh cleaved highly oriented pyrolytic graphite (HOPG) was surface treated with poly-l-lysine for adhesion purpose. By dipping the sample into a colloidal gold solution with particles with a nominal diameter in the range of 30-50 nm, naturally and uniformly dispersed gold nanoparticles are attached to the HOPG surface. These nanoparticles serve as a mask for a subsequent reactive ion etching process to form the graphite nano-cones. Higher etching rates under oxygen plasma were observed at a plasma power above 180 Watts. Depending on the oxygen plasma etching parameters such as power and etching time, nano-cones with different shapes and sizes were fabricated. A sulfur doped boron nitride coating was deposited on the etched HOPG nano-cones using an ion assisted physical vapor deposition technique. Field emission characteristics from different coated and uncoated HOPG nano-cones will be presented along with their thermal and temporal stability measurements under different pressure environments. Acknowledgment: This material is based upon work supported by the National Science Foundation under Grant No. 0010100 and by NASA cooperative agreement to TcSAM. The authors would like to thank Dr. N. Medelci for his valuable help.