Investigation of electric conditions in the vicinity of carbon nanotubes grown in a DC plasma sheath

Carbon nanotubes (CNTs - long tubular carbon nanostructures) belong to the best electron field emitting materials. Based on the experimentally determined electron density in the dual hot filament/DC plasma deposition system the electric field close to the substrate and ion energy flux were calculated. The dependences of electric characteristics close to the nanotube tips on various geometric and plasma parameters were numerically investigated. Taking into account the field enhancement in the vicinity of the CNTs tips the force acting on them was determined. The reliability of numeric computations was tested on a model of conductive sphere placed in a homogeneous electric field, for which theoretical predictions concerning electric forces and field emission currents can be derived.