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

¹ Department of Physics, Indian Institute of Science, Bangalore 560012, India
² Biomolecular Electronics and Nanotechnology Division, Central Scientific Instruments Organization, Chandigarh 160030, India
³ Department of Physics, Panjab University, Chandigarh 160014, India
⁴ Central Electronics Engineering Research Institute, Pilani, Rajasthan, India
⁵ Amity Institute of Nanotechnology, Amity University, Noida, Uttar Pradesh, India

^a e-mail: sureshnano@yahoo.com

Received: 29 August 2013
Revised: 9 October 2013
Accepted: 14 October 2013
Published online: 15 November 2013

Abstract

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.