Self assembly of ordered artificial solids of semiconducting ZnS capped CdSe nanoparticles at carbon nanotube ends

The utilization of carbon nanotubes (CNTs) as building blocks for nanodevices can only be realized when their electronic properties are preserved in the device configuration. It has been shown that bending and overlapping of CNTs result in a decrease in their conductance. Heterojunctions of quantum dots (QDs) and multiwalled carbon nanotubes (MWCNTs) could become better alternatives for the synthesis of nanoscale devices which would preserve the electronic properties of MWCNTs. Here, we present a significant refinement of a previously reported technique to integrate QD at the ends of MWCNTs and report a novel MWCNT–QD–MWCNT heterostructure with detailed chemical and physical characterization of the heterojunctions conducted via Fourier transform infrared spectroscopy, transmission electron microscopy (TEM) and energy dispersive spectroscopy. We have discovered a novel phenomenon of mesoscale ordering of thiol stabilized ZnS capped CdSe QDs containing amine terminal groups at the ends of acid treated MWCNTs during the conjugation process, which has been investigated using high resolution TEM. 2004 Elsevier Ltd. All rights reserved.