Soluble carbon nanotube films treated using a hydrogen plasma for uniform electron field emission

Large-scaled and homogeneous multi-wall carbon nanotube (MWNT) films have been fabricated using the soluble octadecylamine modified multi-wall carbon nanotubes at room temperature by spin-coating method. The characterization, by scanning electron microscopy (SEM), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM) and micro-Raman spectroscopy, shows that the surfaces of the carbon nanotubes with hydrogen plasma (HP) treatment are covered with carbon nanoparticles. Field emission tests indicate that the treated MWNT films have a low turn-on emission field of 0.5 V/μm (at 0.1 μA/cm2), high emission site density (ESD) of approximately 104 cm−2 and high emission current density of 10 mA/ cm2 (at 7.5V/μm). The conversion mechanism of the treated MWNT structure and the reason of changing the field emission characteristic of the MWNT are discussed.