title: Origin and control of blinking in quantum dots.
abstract: Semiconductor nanocrystals offer an enormous diversity of potential device applications, based on their size-tunable photoluminescence, high optical stability and 'bottom-up' chemical approaches to self-assembly. However, the promise of such applications can be seriously limited by photoluminescence intermittency in nanocrystal emission, that is, 'blinking', arising from the escape of either one or both of the photoexcited carriers to the nanocrystal surface. In the first scenario, the remaining nanocrystal charge quenches photoluminescence via non-radiative Auger recombination, whereas for the other, the exciton is thought to be intercepted before thermalization and does not contribute to the photoluminescence. This Review summarizes the current understanding of the mechanisms responsible for nanocrystal blinking kinetics as well as core-shell engineering efforts to control such phenomena. In particular, 'softening' of the core-shell confinement potential strongly suppresses non-radiative Auger processes in charged nanocrystals, with successful non-blinking implementations demonstrated in CdSe-CdS core-thick-shell nanocrystals and their modifications.
authors.affiliation: Naval Research Laboratory, Center for Computational Material Science, Washington DC 20375, USA.
authors.forename: Alexander L
authors.initials: AL
authors.lastname: Efros
authors.affiliation: JILA, University of Colorado and National Institute of Standards and Technology, and Department of Chemistry and Biochemistry, University of Colorado, Boulder, Colorado 80309-0440, USA.
authors.forename: David J
authors.initials: DJ
authors.lastname: Nesbitt