Electron Transfer from Single Semiconductor Nanocrystals to Individual Acceptor Molecules
Links to Fileshttps://pubs.acs.org/doi/10.1021/acsenergylett.6b00047
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Type of Work22 pages
Citation of Original PublicationLeng, Haixu, James Loy, Victor Amin, Emily A. Weiss, and Matthew Pelton. “Electron Transfer from Single Semiconductor Nanocrystals to Individual Acceptor Molecules.” ACS Energy Letters 1, no. 1 (July 8, 2016): 9–15. https://doi.org/10.1021/acsenergylett.6b00047.
RightsThis document is the unedited Author’s version of a Submitted Work that was subsequently accepted for publication in ACS Energy Letters, copyright © American Chemical Society after peer review. To access the final edited and published work see https://doi.org/10.1021/acsenergylett.6b00047.
This Letter reports the measurement of photoinduced electron-transfer rates from individual CdSe/CdS nanocrystals, or quantum dots (QDs), to methyl viologen acceptor molecules adsorbed on the QD surfaces, using time-resolved photoluminescence at the single-nanocrystal level. For each QD measured, the electron-transfer rate is constant over time, and the photoluminescence blinking dynamics are independent of the measured transfer rate. The total electron-transfer rate is distributed in discrete, constant increments, corresponding to discrete numbers of adsorbed molecules on each QD. The results thus validate previous assumptions that viologen molecules adsorb independently on QD surfaces and that the total electron-transfer rate from a single QD to multiple molecules on its surface is simply the sum of the transfer rates to the individual molecules. The measurement provides an optical method to count the number of active acceptor molecules bound to a single nanocrystal and opens up new possibilities for mechanistic studies of charge transfer at the nanoscale.