Documents à télécharger :

• JOURNAL OF APPLIED PHYSICS 105, 094323 (2009) (272 Ko)

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.

JAP online