Optical properties of carbon nanotubes in a composite material: The role of dielectric screening and thermal expansion
Résumé
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]Origine | Fichiers produits par l'(les) auteur(s) |
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