Effect of high voltage annealing on the field emission of multi-walled carbon nanotube film

Non-aligned multi-walled carbon nanotubes were grown using the catalytic thermal CVD method. These CNTs were treated by the high voltage annealing (HVA) for 47 hours. It is found that the HVA is an effective way to stabilize the field emission properties of CNTs film, and it also makes CNT to become more metallic. The stability improvement is quantitatively studied by a simple statistical analysis, which implies a favored voltage level for the best stability improvement using HVA. Possible reasons for the above mentioned observations are discussed.