Electron field emission from Carbon Nanotube Composites: Transport and Local Electric Fields*

Electron field emission characterisation of carbon nanotube polymer composites has been performed where emission at low nanotube mass fractions ($<$10{\%}) has been observed. Nanotubes have been embedded in two different types of polymer: PmPV, a conjugated polymer and PVA, polyvinyl alcohol. It shown that for nanotubes embedded in PmPV, the field emission is strongly influenced by charge transport through the film. For nanotubes in PVA a transition from bulk transport to a Fowler-Nordheim emission mechanism is seen as the mass fraction exceeds about 1-2{\%}. Estimates of the local field as a function of mass fraction are also shown. The potential role of nanotube -- polymer composites produced by solution processing to large area cathodes with a controllable mass fraction will be discussed.