Ultrafast Energy Transfer in a Multichromophoric Layered Silicate

Making use of novel organic/inorganic synthesis, we achieved two-dimensional positioning in chromophores, which were confined to the interlayer of luminous silicate nanofilms synthesized with organoalkoxysilane precursors. Time-resolved photoluminescence demonstrated efficient energy transfer from a donor dye (coumarin) to an acceptor dye (cyanine) with a characteristic time of less than 5 ps. The copresence of slow radiative energy transfer, associated with emission and reabsorption of photons, was also confirmed in the acceptor emission decay. The relative efficiency of the slow and fast energy transfers was quantified, and found to depend on the molecular concentration.