Carbon Nanotubes Array as Novel Thermionic Emitting Materials

It is proposed to investigate the technical feasibility of using aligned nanotubes arrays coated with conformal coating of nanocrystalline diamond as efficient thermionic emitter. Carbon nanotubes and nanocrystalline diamond has recently attracted attention due to their promising electronic and structure properties. Due to the aligned structure and electrical properties of nanotubes and the negative electron affinity of the wide band gap of diamond it is expected that diamond coated aligned nanotubes could be ideal materials for highly efficient electron emitting sources. It is proposed to produce aligned nanotubes with varied growth density, develop and coat with conformal coating of nanocrystalline diamond, and to characterize these novel materials for electron emission behavior. These results will be compared to existing and developmental emitters. The proposed approach if successful can be applied to produce next generation thermionic energy converter.