Fig. 5. Optical response of a quantum dot during a cyclic voltammetry scan demonstrating reproducibility.

(A) FLID of the quantum dot (qd1; blue circles) from batch 1, which has been shown in Figs. 2 to 4, extracted from intensity time traces measured during cyclic voltammetry scans, as shown in (D). (B) FLID of another quantum dot, from batch 2 (qd2; purple circles). In (A) and (B), the red lines represent the statistical scaling model for different Auger rates according to Eqs. 1 and 2. In the cyclic voltammetry scans, the bias was varied linearly in time, as indicated in (C). At t = 10 s, the scan polarity was reversed to return to the initial bias of 0 V. Positive bias caused quenching of the neutral exciton (see an example in fig. S6). (D) Intensity time trace measured during the potential scan of qd1 from batch 1 used to build FLID in (A). After the suppression of blinking around −1.4 V, the photoluminescence intensity was gradually quenched under the linear decrease in the applied potential. The initial photoluminescence intensity was restored when the scan polarity was reversed (an intensity trace of this quantum dot during six voltammetric cycles is shown in fig. S8) and began to blink again around −1.4 V. The time bin is 10 ms.