Charge Transfer Evidence between Carbon Nanotubes and Encapsulated Conjugated Oligomers

Laurent Alvarez (1) , Yann Almadori (1) , Raul Arenal (2, 3) , Moulay-Rachid Babaa (4, 5) , Thierry Michel (1) , Rozenn Le Parc (1) , Jean-Louis Bantignies (1) , Bruno Jousselme (4) , Serge Palacin (4) , Patrick Hermet (1) , Jean-Louis Sauvajol (1)

1 L2C - Laboratoire Charles Coulomb
2 LEM - ONERA - CNRS - Laboratoire d'étude des microstructures [Châtillon]
3 INA - Instituto de Nanociencia de Aragón [Saragoza, España]
4 LCSI - Laboratoire de Chimie des Surfaces et Interfaces
5 UTP - Universiti Teknologi PETRONAS

A hybrid system consisting of quaterthiophene derivative inserted into carbon nanotubes is studied. Encapsulation efficiency of the conjugated oligomers in the hollow core of nanotubes is investigated by transmission electron microscopy and spatial-resolved electron energy loss spectroscopy. Infrared spectroscopy showed evidence of a significant positive charge transfer on the inserted oligothiophene. Raman spectra display different behaviors depending on the excitation energy and correlated to the quaterthiophene optical absorption energy. At high excitation wavelength (far from the oligomer resonance), radial breathing modes exhibit a significant upshift consistent with an encapsulation effect. At low excitation wavelength (close to the oligomer resonance), both the G-band shift and the low-frequency modes vanishing suggest a significant charge transfer between the quaterthiophene and the nanotubes

Keywords: SPECTRA; RENORMALIZATION; RAMAN-SPECTROSCOPY; FUNCTIONALIZATION; END-CAPPED OLIGOTHIOPHENES; SERIES

Domains: Chemical Sciences; Material chemistry

Laurent Alvarez, Yann Almadori, Raul Arenal, Moulay-Rachid Babaa, Thierry Michel, et al.. Charge Transfer Evidence between Carbon Nanotubes and Encapsulated Conjugated Oligomers. Journal of Physical Chemistry C, 2011, 115, pp.11898-11905. ⟨10.1021/jp1121678⟩. ⟨cea-00960683⟩