Semiconductor quantum dots (QDs) in small clusters can exchange excited state energy via various transfermechanisms such as Forster resonant energy transfer (FRET). Such energy transfer enables excitons to move fromlarger bandgap donors to smaller bandgap acceptors. Clusters of mixed donor/acceptor QD species consequentlyhave a spectral signature that is dependent on which QDs in the clusters are responsible for the emission. Usinga dual-color super-resolution imaging approach, we report on the spectral characteristics of interacting QDs inclusters with nanometer spatial resolution. Higher emission intensities from clusters are shown to emanate fromsub-regions of the clusters and have spectral signatures that indicate the emission is dominated by the acceptorregion of the spectrum. Thus, energy transferring interactions among QDs in clusters funnel excitons primarilyto acceptor particles. Acceptor particles are responsible for the majority of the emission from the clusters withan emission spectra corresponding to the spectral profiles of the acceptor species.
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