Ternary Chalcogenide-Based Quantum Dots and Carbon Nanotubes: Establishing a Toolbox for Controlled Formation of Nanocomposites.

A general procedure based on electrostatic self-assembly for preparing nanocomposites based on carbon nanotubes (CNTs) and ternary chalcogenide semiconductor nanoparticles is shown. This was achieved by surface functionalization of the single components through well-established protocols, for CNTs, and a transferable general strategy for the nanoparticles. Heterostructures were then synthesized through electrostatic interaction between oppositely charged components.

Tuning the Optical Band Gap of Semiconductor Nanocomposites-A Case Study with ZnS/Carbon.

The linear photochemical response of materials depends on two critical parameters: the size of the optical band gap determines the onset of optical excitation, whereas the absolute energetic positions of the band edges define the reductive or oxidative character of photo-generated electrons and holes. Tuning these characteristics is necessary for many potential applications and can be achieved through changes in the bulk composition or particle size, adjustment of the surface chemistry or the application of electrostatic fields. In this contribution the influence of surface chemistry and fields is investigated systematically with the help of standard DFT calculations for a typical case, namely composites prepared from ZnS quantum dots and functionalized carbon nanotubes.