Electrochemical Raman spectroscopy of carbon nanotube energy transfer complexes

Abstract

We present electrochemical Raman measurements on energy transfer complexes formed by combining single-walled carbon nanotubes and dye molecules. The presence of the dye molecules in the proximity of the nanotubes impacts the nanotubes’ charging behavior, leading to changes in the position of the charge neutrality point and the maximum achievable doping strength. We compare these results to spectra acquired in solution and determine the corresponding Fermi energy shifts, which are found to be similar in the energy transfer complexes and a reference sample. Our results have implications for the photoluminescence enhancement/quenching previously observed in these energy transfer complexes. Electrochemical G-mode Raman spectra at a gate voltage of −1.1 V showing much larger doping strength for the reference sample than for the energy transfer complexes, as seen in the higher-frequency and narrower peak.