000225643 001__ 225643
000225643 005__ 20181203024546.0
000225643 0247_ $$2doi$$a10.1038/nature10569
000225643 022__ $$a1476-4687
000225643 037__ $$aARTICLE
000225643 245__ $$aTwo types of luminescence blinking revealed by spectroelectrochemistry of single quantum dots
000225643 260__ $$c2011
000225643 269__ $$a2011
000225643 336__ $$aJournal Articles
000225643 520__ $$aPhotoluminescence blinking—random switching between states of high (ON) and low (OFF) emissivities—is a universal property of molecular emitters found in dyes1, polymers2, biological molecules3 and artificial nanostructures such as nanocrystal quantum dots, carbon nanotubes and nanowires4, 5, 6. For the past 15 years, colloidal nanocrystals have been used as a model system to study this phenomenon5, 6. The occurrence of OFF periods in nanocrystal emission has been commonly attributed to the presence of an additional charge7, which leads to photoluminescence quenching by non-radiative recombination (the Auger mechanism)8. However, this ‘charging’ model was recently challenged in several reports9, 10. Here we report time-resolved photoluminescence studies of individual nanocrystal quantum dots performed while electrochemically controlling the degree of their charging, with the goal of clarifying the role of charging in blinking. We find that two distinct types of blinking are possible: conventional (A-type) blinking due to charging and discharging of the nanocrystal core, in which lower photoluminescence intensities correlate with shorter photoluminescence lifetimes; and a second sort (B-type), in which large changes in the emission intensity are not accompanied by significant changes in emission dynamics. We attribute B-type blinking to charge fluctuations in the electron-accepting surface sites. When unoccupied, these sites intercept ‘hot’ electrons before they relax into emitting core states. Both blinking mechanisms can be electrochemically controlled and completely suppressed by application of an appropriate potential.
000225643 700__ $$0247423$$g172230$$aGalland, Christophe
000225643 700__ $$aGhosh, Yagnaseni
000225643 700__ $$aSteinbrück, Andrea
000225643 700__ $$aSykora, Milan
000225643 700__ $$aHollingsworth, Jennifer A.
000225643 700__ $$aKlimov, Victor I.
000225643 700__ $$aHtoon, Han
000225643 773__ $$j479$$tNature$$k7372$$q203-207
000225643 909C0 $$xU13462$$0252619$$pLQNO
000225643 909CO $$pSB$$particle$$ooai:infoscience.tind.io:225643
000225643 917Z8 $$x172230
000225643 917Z8 $$x148230
000225643 917Z8 $$x173008
000225643 937__ $$aEPFL-ARTICLE-225643
000225643 973__ $$rREVIEWED$$sPUBLISHED$$aOTHER
000225643 980__ $$aARTICLE