arXiv:1002.4102v1 [cond-mat.mes-hall] 22 Feb 2010 1 The observed intermittent light emission from colloidal semiconductor nanocrystals has long been associated with Auger recombination assisted quenching. We test this view by observing transient emission dynamics of CdSe/CdS/ZnS semiconductor nanocrystals using time-resolved photon counting. The size and intensity dependence of the observed decay dynamics are incon- sistent with the those expected from Auger processes. Moreover, the data suggests that in the ‘off’ state the quantum dot cycles in a three-step process: photoexcitation, rapid trapping and subsequent slow nonradiative decay. Abstract Photodarkening of blinking quantum dots is not governed by Auger recombination Shamir Rosen, Osip Schwartz and Dan Oron 1 $^{1}$Department of Physics of Complex Systems, Weizmann Institute of Science, Rehovot, Israel