Fast Energy Transfer in CdSe Quantum Dot Layered Structures: Controlling Coupling with Covalent-Bond Organic Linkers

Eyal Cohen1, Pavel Komm1, Noa Rosenthal-Strauss1, Joanna Dehnel2, Efrat Lifshitz2, Shira Yochelis1, R. D. Levine3, Francoise Remacle4, Barbara Fresch5, Gilad Marcus1, Yossi Paltiel1,6.

1Department of Applied Physics, 6Center for Nano-Science and Nano-Technology, 3The Fritz Haber Center for Molecular Dynamics and Institute of Chemistry, The Hebrew University of Jerusalem, Jerusalem 9190401, Israel; 2Schulich Faculty of Chemistry, Solid State Institute and Rusell Berrie Nanotechnology Institute, Technion, Haifa 3200003, Israel; 4Theoretical Physical Chemistry, UR MolSys, University of Liege, B4000 Liege, Belgium; 5Department of Chemical Science, University of Padova, Via Marzolo 1, 35131 Padova, Italy
The Journal of Physical Chemistry C, 2018, published on line.

KEYWORDS: Semiconductor nanocrystals, excitonic energy transfer, organic linkers, transient absorption.


Quantum dots (QDs) solids and arrays hold a great potential for novel applications, aiming at exploiting of quantum properties in room temperature devices. Careful tailoring of the QDs energy levels and coupling between dots could lead to efficient energy harvesting devices. Here we used a self-assembly method to create a disordered layered structure of QDs, coupled by covalently binding organic molecules. Energy transfer rates from small (donor) to large (acceptor) QDs are measured. Best tailoring of the QDs energy levels and the linking molecules length, result in an energy transfer rate as fast as (30ps)-1. Such rates approach energy transfer rates of the highly efficient photosynthesis complexes, and are compatible with a coherent mechanism of energy transfer. These results may pave the way for new controllable building blocks for future technologies.