Enhancement of field emission from hydrogen plasma processed carbon nanotubes

An effective approach to improve the field emission site density and large area uniformity of carbon nanotube (CNT) films has been presented. I-V characteristics, Raman spectra, as well as surface morphology and microstructure of the CNT films before and after the hydrogen plasma process (HPP) were investigated. Results showed that after the HPP nano-nodes appeared along the tubes and the field electron emission site density increased dramatically from 10 ³ to 10 ⁶ cm ^{- 2} . A model for the formation of the nodular CNTs was proposed. We attributed this improvement to the changing of the electronic and/or geometrical structure of the local emission region in CNTs.