Improving the emission characteristics of a carbon nanotube film in NaCl electrolyte

Screen printing is undoubtedly the most cost-effective process for the fabrication of large-sized carbon nanotube field emission display (CNT-FED). A novel post-treatment method in NaCl electrolyte was presented to solve the problem of poor field emission characteristics of printed CNT films. Compared to those of untreated films, the turn-on electric field of the treated film decreased from 2.4 to 1.4 V/μm and the total emission current of the treated film that has the same printing area as the untreated one increased from ∼100 to ∼1800 μA. Scanning electron microscope (SEM) and Raman spectrum study revealed that field emission characteristics are enhanced by two factors. Firstly, the NaCl electrolyte treatment appeared to render the CNT surfaces more activey by exposing more CNTs from the CNT film. Secondly, the numerous defects of CNTs of the CNT film were increased by electrical current energy.