Unifying the low-temperature photoluminescence spectra of carbon nanotubes: the role of acoustic phonon confinement.

Fabien Vialla (1) , Yannick Chassagneux (1) , Robson Ferreira (1) , Cyrielle Roquelet (2) , Carole Diederichs (1) , Guillaume Cassabois (3) , Philippe Roussignol (1) , Jean‐sébastien Lauret (2) , Christophe Voisin (1)

1 LPA - Laboratoire Pierre Aigrain
2 LAC - Laboratoire Aimé Cotton
3 L2C - Laboratoire Charles Coulomb

At low temperature the photoluminescence of single-wall carbon nanotubes show a large variety of spectral profiles ranging from ultra narrow lines in suspended nanotubes to broad and asymmetrical line-shapes that puzzle the current interpretation in terms of exciton-phonon coupling. Here, we present a complete set of photoluminescence profiles in matrix embedded nanotubes including unprecedented narrow emission lines. We demonstrate that the diversity of the low-temperature luminescence profiles in nanotubes originates in tiny modifications of their low-energy acoustic phonon modes. When low energy modes are locally suppressed, a sharp photoluminescence line as narrow as 0.7 meV is restored. Furthermore, multi-peak luminescence profiles with specific temperature dependence show the presence of confined phonon modes.

Domaines: Autre [cond-mat.other]

Fabien Vialla, Yannick Chassagneux, Robson Ferreira, Cyrielle Roquelet, Carole Diederichs, et al.. Unifying the low-temperature photoluminescence spectra of carbon nanotubes: the role of acoustic phonon confinement.. Physical Review Letters, 2014, 113, pp.057402. ⟨10.1103/PhysRevLett.113.057402⟩. ⟨hal-01066160⟩