Field emission of zinc oxide nanowires grown on carbon cloth

An extremely low operating electric field has been achieved on zinc oxide (ZnO) nanowire field emitters grown on carbon cloth. Thermal vaporization and condensation was used to grow the nanowires from a mixture source of ZnO and graphite powders in a tube furnace. An emission current density of 1mA∕cm2 was obtained at an operating electric field of 0.7V∕μm. Such low field results from an extremely high field enhancement factor of 4.11×104 due to a combined effect of the high intrinsic aspect ratio of ZnO nanowires and the woven geometry of carbon cloth.