Surface Charge Control of Quantum Dot Blinking

Steven D. Quinn, Aidan Rafferty, Emma Dick, Michael J Morten, Fraser J. Kettles, Chloe Knox, Mark Murrie*, Steven W. Magennis

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review


A characteristic property of colloidal semiconductor nanocrystal quantum dots (QDs) is their emission intermittency. Although a unifying theory of QD photoprocesses remains elusive, the importance of charged states is clear. We now report a new approach to directly study the role of surface charge on QD emission by adding metal ions to individual, core-only QDs immobilized in aqueous solution in an agarose gel. The CdTe QDs show very stable emission in the absence of metal ions but a dramatic and reversible increase in blinking due to the presence of trivalent metal ions. Our results support a charge-separation model, in which the major blinking pathway is the surface trapping of electrons; transiently bound metal ions close to the QD surface enhance this process.

Original languageEnglish
Pages (from-to)19487-19491
Number of pages5
JournalJournal of Physical Chemistry C
Issue number34
Publication statusPublished - 1 Sept 2016

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