Gated Carbon Nanotube Pillar Arrays for High Current Applications
Abstract
Carbon nanotubes (CNTs) are attractive electron sources because of their mechanical stability, high electrical conductivity, and low turn-on fields. These properties make CNTs attractive candidates for a number of possible applications, in particular, those requiring high current densities such as travelling wave tube amplifiers and electric propulsion systems. In addition to high emission current density, a generally desirable operational parameter of cathodes is low electron extraction voltage. This is achievable with an array of emitters in which each of the emitters is fabricated with its own extracting electrode at a close distance. This concept has been previously developed for microfabricated Si cathodes. Similar cathode structures have been investigated for carbon nanostructure emitters, however, a number of challenges have been insurmountable, namely the inability to fabricate an individual CNT array in a controlled manner. This limitation has hindered the success of such cathode structures. To address this issue, in this work, we will introduce an integrated gated array of controlled CNT cathodes based on our previously demonstrated, highly stable carbon nanotube pillar array. A detailed fabrication process for this cathode structure will also be presented.
Document Details
- Document Type
- Technical Report
- Publication Date
- Apr 01, 2008
- Accession Number
- ADA493424
Entities
People
- Bryan Ribaya
- Cattien V. Nguyen
- Darrell L. Niemann
- Jeremy Silan
- Jessica L. Killian
- Mahmudur Rahman
Organizations
- National Aeronautics and Space Administration