Field emission characteristics of amorphous carbon and diamond emitters

Amorphous carbon and diamond coated emitters have been used to examine field emission characteristics. Amorphous carbon is coated by a new process named helical resonator plasma enhanced chemical vapor deposition. An amorphous carbon emitter with broad disordered graphite peak and small wavenumber of graphite exhibits a better I-V characteristic than that with an intense disordered graphite peak and large wavenumber of graphite. Field emission from diamond coated emitters shows enhancement both in turn-on voltage and total emission current. Diamond coated emitters have a considerable amount of graphite which may allow continuous low field emission. We think that negative electron affinity and graphite inclusions seem to improve the field emission characteristics. However, further work is necessary to exactly clarify the mechanism for low field emission.