Emission characterization from nitrogen-doped diamond with respect to energy conversion

Vacuum thermionic energy converters utilize electron emissive materials as a key component in the transformation of thermal into electrical energy. Electron emission from nitrogen-doped diamond films was characterized with respect to the thermionic emission relation derived by Richardson–Dushman. Key parameters, which describe the emitter material, are the work function φ and the Richardson constant A. A fitting procedure has been employed to determine φ and A for nitrogen-doped diamond. However, a simultaneous solution to the Richardson–Dushman relation was limited due to the strongly coupled parameters φ and A. Additionally, the emission was characterized at various applied fields indicating a change in the electronic structure of the material contrary to classical thermionic emitters.