Role of sp2 phase in field emission from nanostructured carbons

It is shown that sp(2) phase organization plays an important role in the field emission from nanostructured carbons. Emission is found to depend on the cluster size, anisotropy, and mesoscale bonding of the sp(2) phase, and the electronic disorder. It is found by Raman spectroscopy that increasing the size of sp(2) clusters in the 1-10 nm range improves emission. Anisotropy in the sp(2) phase orientation can help or inhibit the emission. sp(2) clusters embedded in the sp(3) matrix or electronic disorder induced by localized defects oriented in the field direction can provide a local field enhancement to facilitate the emission. (C) 2001 American Institute of Physics.