Conductivity modulation of carbon nanotubes through hybridization with quantum dots and gold nanoparticles

CdSe/ZnS quantum dots and gold nanoparticles have been grown in-situ onto the surface of carbon nanotubes. The nanohybrids were then, dielectrophoretically aligned between gold microelectrodes and the electrical response was investigated. The conductance of nanotube-quantum dot hybrid was found to be sensitive to incident white light. The electrical resistance of the carbon nanotube-quantum dot nanohybrid decreased from 1.9 × 104 Ω (in the dark) to 0.91 × 104 Ω after the impact of white light. The electrical resistance of the carbon nanotube-gold nanoparticle nanohybrid was calculated to be 1.86 × 103 Ω, which is much smaller than that of carboxylated carbon nanotubes (4.03 × 105 Ω). Such a modulation in electrical properties may enhance the use of carbon nanotubes in future nanoscale devices.