Direct Formation of Graphene-Carbon Nanotubes Hybrid on SiO_2 Substrate via Chemical Vapor Deposition

摘要

Graphene-carbon nanotubes hybrid was directly synthesized via chemical vapor deposition using Ni foil as catalyst for the decomposition of carbon source. On an unpolished SiO_2 substrate with many SiO_2 nanodots, graphene film grows directly on the substrate while carbon nanotubes sprout out from SiO_2 nanodot on the top of graphene where Ni element was not detected. The density and length of carbon nanotubes can be controlled via changing the chemical vapor deposition growth time. The hybrid film is highly transparent and conductive, showing a sheet resistance of ～600 Ω/□ at 90% transmittance (at 550 nm). Finally the hybrid equipped with two parallel rectangular electrodes appears to be efficient humidity sensors.