Super-resolution photoluminescence lifetime and intensity mapping of interacting CdSe/CdS quantum dots

摘要

We report an optical imaging method that simultaneously achieves nanometer-scale spatial resolution and records single-photon arrival times with subnanosecond temporal resolution, allowing for visualization of nanoscale photoluminescence dynamics. The technique combines time-correlated single-photon counting with single-molecule localization microscopy by monitoring the emission centroid location with a 2 x 2 array of optical fibers that are coupled to four single-photon counting detectors. We applied this method to image isolated and clustered CdSe/CdS core/shell quantum dots (QDs). Single QDs were localized with similar to 5 nm precision using 10(4) detected photons. Within clusters, emission centroids separated by similar to 12 nm were resolved, and spatial mapping of both the emission intensity and lifetime provided evidence of energy transport pathways among the QDs.