Department of Physics SCHOOL OF NATURAL SCIENCES & MATHEMATICS

Energy Transfer between J-Aggregate/NQD Hybrid Structures

Aggregates of the cyanine dyes are a class of fluorophores with greatly enhanced absorption and emission properties resulting from the coherent coupling of tens to hundreds of aligned monomer molecules. Tuning the aggregate structure influences the intermolecular excitonic interactions that couple to the optical transitions of the individual molecules in the aggregate. As such, J-aggregates of cyanine dyes have received considerable attention in regard to their applications in optoelectronics and sensors.

We study near-field (dipole -dipole) interactions in blends and multilayers of J-Aggregates and colloidal CdSe nanocrystals. It recently has been found that nanocrystals can transfer excitonic energy to JAs via near field, Forster-type interaction in layered structures across ~20 nm distance. [1] Hence, such hybrid system may present considerable interest in structures relying on the orderly energy flow and in optical “antennae” systems. We had been employing J-aggregates (TDBC and TCC) in layered structures with “giant” nanocrystals (in collaboration with group of Dr. Hollingsworth at LANL) to aid in energy extraction from optical excited nanoparticles. [2]

References:

[1] Q.  Zhang, T. Atay, J.R. Tischler, M. S. Bradley, V. Bulovic´, and A. V. Nurmikko, “Highly efficient resonant coupling of optical excitations in hybrid organic/inorganic semiconductor nanostructures”, Nature Nanotechnology2, 555 (2007)
[2]
A. Radja, H. M. Nguyen, J. A. Hollingsworth and A.V. Malko, “Ultrafast exciton energy transfer from giant nanocrystals to layered J-aggregate films”, American Physical Society Meeting, 2013