Room-Temperature Micron-Scale Exciton Migration in a Stabilized Emissive Molecular Aggregate.
We report 1.6 ± 1 μm exciton transport in self-assembled supramolecular light-harvesting nanotubes (LHNs) assembled from amphiphillic cyanine dyes. We stabilize LHNs in a sucrose glass matrix, greatly reducing light and oxidative damage and allowing the observation of exciton-exciton annihilation signatures under weak excitation flux. Fitting to a one-dimensional diffusion model, we find an average exciton diffusion constant of 55 ± 20 cm2/s, among the highest measured for an organic system. We develop a simple model that uses cryogenic measurements of static and dynamic energetic disorder to estimate a diffusion constant of 32 cm2/s, in agreement with experiment. We ascribe large exciton diffusion lengths to low static and dynamic energetic disorder in LHNs. We argue that matrix-stabilized LHNS represent an excellent model system to study coherent excitonic transport.
Justin R
JR
Caram
Sandra
S
Doria
Department of Chemistry and Biochemistry, Center for Discovery and Innovation, The City College of New York of The City University of New York , 160 Convent Avenue, New York, New York 10031 United States.
Dörthe M
DM
Eisele
Francesca S
FS
Freyria
Timothy S
TS
Sinclair
Patrick
P
Rebentrost
Seth
S
Lloyd
Moungi G
MG
Bawendi
J-aggregate; coherent exciton; exciton; exciton delocalization; exciton diffusion; molecular aggregate