Energy transfer in carbon nanotube/chromophore compounds
In the field of photovoltaic, hybrid organic solar cells are one of the most promising ways, especially due to the light collection properties of chromophore molecules. On the other hand, carbon nanotubes are quasi one-dimensional nano-objects showing exceptional transport properties. The achievement of a significant coupling between a light harvesting molecule and a carbon nanotube is an important route to explore. This research is dedicated to the study of energy transfer in carbon nanotube/chromophore compounds. A new method of non-covalent functionalization of carbon nanotubes is presented. Based on a micellar suspension of nanotubes, this method provides a high degree of functionalization while preserving the intrinsic properties of nanotubes. The energy transfer is shown in nanotube/porphyrin compounds by photoluminescence excitation spectroscopy on ensembles as well as at the single molecule scale. The evaluation of the quantum efficiency of the transfer by three independent methods shows a coupling of the order of 100% between the molecule and the nanotube, despite the weak interactions between “Pi” orbitals involved in the non-covalent functionalization. The final part of this work is dedicated to anisotropy measurements on single compounds to gain information on molecular arrangement on the surface of nanotubes.