Disorder Limited Exciton Transport in Colloidal Single-Wall Carbon Nanotubes
Idioma
en
Article de revue
Este ítem está publicado en
Nano Letters. 2012-09-17p. in press
American Chemical Society
Resumen en inglés
We present measurements of S1 exciton transport in (6,5) carbon nanotubes at room temperature in a colloidal environment. Exciton diffusion lengths associated with end quenching paired with photoluminescence lifetimes ...Leer más >
We present measurements of S1 exciton transport in (6,5) carbon nanotubes at room temperature in a colloidal environment. Exciton diffusion lengths associated with end quenching paired with photoluminescence lifetimes provide a direct basis for determining a median dif- fusion constant of approximately 7.5 cm2s-1. Our experimental results are compared to model diffusion constants calculated using a realistic exciton dispersion accounting for a logarithmic correction due to the exchange self-energy and a non-equilibrium distribution between bright and dark excitons. The intrinsic diffusion constant associated with acoustic phonon scattering is too large to explain the observed diffusion length, and as such, we attribute the observedtransport to disorder-limited diffusional transport associated with the dynamics of the colloidal interface. In this model an effective surface potential limits the exciton mean free path to the same size as that of the exciton wavefunction, defined by the strength of the electron-hole Coulomb interaction.< Leer menos
Palabras clave en inglés
carbon nanotube
exciton
dephasing
transport
exchange interaction
Orígen
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