Electrical control of Förster energy transfer

The direct control of the spectral resonance between the donor and acceptor required for nanoscopic Förster-type energy transfer in single nanorod dye couples is discussed. The emission from single dye molecules can be controlled electrically, with the far-field manipulation of a near-field phenomenon. This effect lead to the design of single molecule optoelectronic switches providing building blocks for more complex nanophotonic circuitry. Excitation energy can be transferred from the nanocrystal to the dye molecules was done by providing sufficient spectral overlap between the emission of a single nanocrystal and the absorption of a nearby dye molecule. Single nanocrystals exhibit a substantial Stark shift of the emission spectrum in the presence of an external electric field. The local changes in the dielectric environment controls the magnitude of field screening, as the rate of energy transfer depends sensitively on the electric field.