Thermionic Converters Based on Nanostructured Carbon Materials

"The goal of this program is the development of thermionic energy converters based on nanostructured carbon materials. Nanocrystalline diamond and carbon nanotube materials exhibit unusual electron emission properties which should lead to an all newtechnology for low temperature thermionic energy conversion. Recent results have established that these materials exhibit bright emission sites with field enhancement factors approaching or greater than 1000. In this program PTS Co and researchers fromNC State will team to demonstrate the effectiveness of thermionic emission using nanostructured carbon materials. Both doped and undoped nanocrystalline diamond and aligned carbon nanotube films will be produced by microwave plasma chemical vapordeposition at NC State. The field enhancement factors of the films will be established and the emission stability of the nanostructured carbon materials will be recorded. A new physics based model including thermionic-field emission sites and quantummechanical tunneling will be developed. The materials results and physics based model will be combined to define a prototype system to be constructed in the Phase II program. The development of a new technology for low temperature thermionic energyconversion will lead to numerous commercial and military applications that require power generation from remote thermal sources. Spin off technology such as cold cathodes will have applications to Vacuum Microel