Highly enhanced field emission from CuO nanowire arrays by coating of carbon nanotube network films

Vertically aligned CuO nanowires are coated with CNT network films to achieve a significant improvement in field electron emission. The turn-on field of CuO nanowire array cathodes is decreased from 6.6 V/μm to below 1.2 V/μm owing to the CNT film coating. Compared to the needle-like CuO structures that could perforate the CNT film coating, CuO nanowires with uniform diameter are more suitable to be wrapped by CNT network films from top to bottom. It is found that the coverage of CNTs over CuO nanowire surface plays a role in affecting the turn-on fields and emission stabilities.