Figure 7.

a) Typical emission time trajectory from a single NC. The intensity flickers between “on” and “off” states. Whereas every electron–hole pair recombine radiatively during the “on” state, the ejection of one of the charge carriers to a surface trap results in the SCNC moving into the “off” state, where the exciton recombines through a trap state, or alternatively the core is left charged, which leads to an enhanced nonradiative Auger process with another exciton. b) Two ways to eliminate blinking: either by growing a thick shell which prevents tunneling of one of the charge carriers to surface traps or by growing a graded shell which suppresses the Auger process.