Filament discharge enhances field emission properties by making twisted carbon nanofibres stand up

Twisted carbon nanofibres, named carbon nanotwists, in a flocculated form were pasted, printed on the conductive silicon substrate and then treated by dielectric barrier discharge using He and N2 gases. Vertically upright nanofibres were clearly obtained by 'filament discharge mode' in N2 gas. As the treating time increased up to ~60 s, the height of the nanofibre tips became uniform. Consequently, the field emission property was greatly enhanced and showed a threshold electric field of 4.6 V mum-1 and a maximum current of 0.433 mA cm-2 at 8 V mum-1.