Luminescence properties of individual empty and water-filled single-walled carbon nanotubes.
The influence of water filling on the photoluminescence (PL) properties of SWCNTs is studied by ensemble and single-molecule PL spectroscopy. Red-shifted PL and PL excitation spectra are observed upon water filling for 16 chiralities and can be used to unambiguously distinguish empty SWCNTs from filled ones. The effect of water filling on the optical transitions is well-reproduced by a continuum dielectric constant model previously developed to describe the influence of the nanotube outer environment. Empty nanotubes display narrower luminescence lines and lower inhomogeneous broadening, signatures of reduced extrinsic perturbations. The radial breathing mode phonon sideband is clearly observed in the PL spectrum of small diameter empty tubes, and a strong exciton-phonon coupling is measured for this vibration. Biexponential PL decays are observed for empty and water-filled tubes, and only the short-living component is influenced by the water filling. This may be attributed to a shortening of the radiative lifetime of the bright state by the inner dielectric environment.
Experimental Condensed Matter Physics Laboratory, University of Antwerp, B-2610 Wilrijk, Belgium.
Sofie
S
Cambré
Silvia M
SM
Santos
Wim
W
Wenseleers
Ahmad R T
AR
Nugraha
Riichiro
R
Saito
Laurent
L
Cognet
Brahim
B
Lounis