Electronic properties and field emission of carbon nanotube films treated by hydrogen plasma.

Large-scale and very even multi-wall carbon nanotube (MWNT) films have been obtained at room temperature by an electrophoresis deposition technique. The characterization, by means of scanning electron microscopy, transmission electron microscopy, high-resolution transmission electron microscopy, and micro-Raman spectroscopy, shows that the MWNTs with hydrogen-plasma (HP) treatment are covered by onion-like nanolumps, and three-dimensional multiple-way- connected nanotube webs are formed. The electronic property of the treated MWNT film is converted from semiconducting to metallic. The field-emission test indicates that the HP-treated MWNT film has a low threshold of 1.1 V/μm (at 0.1 μA/cm[SUP2]), a high emission light spot density of about 105 cm[SUP-2], and a stable and suitable emission current. The conversion mechanism of the treated carbon nanotube structure and the reason for the change of the electronic and field-emission characteristics of the MWNT films are discussed. [ABSTRACT FROM AUTHOR]