Highly efficient nonradiative energy transfer using charged CdSe/ZnS nanocrystals for light-harvesting in solution

We propose and demonstrate highly efficient nonradiative Förster resonance energy transfer (FRET) facilitated by the use of positively charged CdSe/ZnS core-shell nanocrystals (NCs) for light-harvesting in solution. With rhodamine B dye molecules used as the acceptors, our time-resolved photoluminescence measurements show substantial lifetime modifications of these amine-functionalized NC donors from 18.16 to 1.88 ns with FRET efficiencies >90% in solution. These strong modifications allow for light-harvesting beyond the absorption spectral range of the acceptor dye molecules.