Electrical conductivity of single-wall carbon nanotube film deposited by electrostatic layer-by-layer assembly with the aid of polyelectrolytes

A single-wall carbon nanotube film was deposited by the sequential deposition of positively charged single-wall carbon nanotube with poly diallyldimethylammonium and negatively charged single-wall nanotube with poly sodium 4-styrenesulfonate. The sequential deposition was repeated 10 times and Al was used as an electrode to measure the electrical conductivity of the film. Electrochemical impedance spectroscopy showed that the film had two semicircles with the resistances of 300 and 1700 Ω, representing single-wall carbon nanotube and polyelectrolyte parts, respectively. The conductivity of the film was enhanced when the water molecules were removed by heat treatment. The analysis of the J-V characteristics indicates that the mechanism of the charge transfer through the single-wall carbon nanotube-polyelectrolyte film is quantum mechanical tunneling.