Study on the vacuum breakdown in field emission of a nest array of multi-walled carbon nanotube/silicon nanoporous pillar array

A composite structure, a nest array of multi-walled carbon nanotubes/silicon nanoporous pillar array (NACNT/Si-NPA), with good field emission properties, was synthesized through growing CNT on Si-NPA by thermal chemical vapor deposition. In order to make full use of its good field emission properties, the vacuum breakdown behavior accompanied with field emission from NACNT/Si-NPA was investigated. The results revealed that a positive feedback of field emission and resulted Joule heat ignited a small portion of protruding emitters, which caused spark discharge, destroyed the anode and generated a large amount of heat. The thermal runaway ultimately resulted in the destruction of substrate and vacuum breakdown.