Optical properties of carbon nanotubes in a composite material: The role of dielectric screening and thermal expansion

Sébastien Berger (1) , Florian Iglésias (1) , Pierre Bonnet (1) , Christophe Voisin (1) , Guillaume Cassabois (1) , Jean‐sébastien Lauret (2) , Claude Delalande (1) , Philippe Roussignol (1)

1 LPA - Laboratoire Pierre Aigrain
2 LPQM - Laboratoire de Photonique Quantique et Moléculaire

We report on environmental effects on the optical properties of single-wall carbon nanotubes in a gelatin-based composite material designed to foster their photoluminescence. We show that the dielectric screening of excitons due to the surrounding medium is responsible for a sizeable shift of the luminescence lines, which hardly depends on the tube geometry. In contrast, the temperature dependence from 4 to 300 K of the luminescence is clearly chirality dependent; the first and second excitonic lines shift in opposite directions with a magnitude that can be related quantitatively to a strain-induced modification of the electronic structure due to an expansivity mismatch between the nanotube and the matrix.

Domaines: Autre [cond-mat.other]

Sébastien Berger, Florian Iglésias, Pierre Bonnet, Christophe Voisin, Guillaume Cassabois, et al.. Optical properties of carbon nanotubes in a composite material: The role of dielectric screening and thermal expansion. Journal of Applied Physics, 2009, 105, pp.094323. ⟨hal-00384084⟩