Field emission of carbon nanotube films fabricated by vacuum filtration

Electron field emission properties of carbon nanotube (CNT) films fabricated by vacuum filtration were studied. CNT films of different filtration volumes (from 10 to 200 ml) were transferred to conductive substrates, and we studied their electron field emission performance. When the filtration volume was less than 50 ml, the CNT film appeared transparent. The optimum result (75 ml sample) was achieved with a low turn-on field of 0.93 V/μm (at 1 μA/cm2) and a high field enhancement factor β of ∼9720, and showed stable emission after aging for 10 h. The CNT film transfer process was explained by interfacial energy properties.