Rabouw Freddy T, Antolinez Felipe V, Brechbühler Raphael, Norris David J
Optical Materials Engineering Laboratory, Department of Mechanical and Process Engineering , ETH Zurich , 8092 Zurich , Switzerland.
J Phys Chem Lett. 2019 Jul 5;10(13):3732-3738. doi: 10.1021/acs.jpclett.9b01348. Epub 2019 Jun 21.
Nearly all colloidal quantum dots, when measured at the single-emitter level, exhibit fluorescence "blinking". However, despite over 20 years of research on this phenomenon, its microscopic origins are still debated. One reason is a gap in available experimental information, specifically for dynamics at short (submillisecond) time scales. Here, we use photon-correlation analysis to investigate microsecond blinking events in individual quantum dots. While the strongly distributed kinetics of blinking normally makes such events difficult to study, we show that they can be analyzed by excluding photons emitted during long bright or dark periods. Moreover, we find that submillisecond blinking events are more common than one might expect from extrapolating the power-law blinking statistics observed on longer (millisecond) time scales. This result provides important experimental data for developing a microscopic understanding of blinking. More generally, our method offers a simple strategy for analyzing microsecond switching dynamics in the fluorescence of quantum emitters.
几乎所有的胶体量子点，在单发射体水平上进行测量时，都会表现出荧光“闪烁”现象。然而，尽管对这一现象进行了20多年的研究，其微观起源仍存在争议。一个原因是现有实验信息存在空白，特别是关于短（亚毫秒）时间尺度下的动力学信息。在此，我们利用光子关联分析来研究单个量子点中的微秒级闪烁事件。虽然闪烁的动力学分布通常使得此类事件难以研究，但我们表明，通过排除在长亮或长暗周期发射的光子，可以对它们进行分析。此外，我们发现亚毫秒级闪烁事件比从较长（毫秒）时间尺度上观察到的幂律闪烁统计推断出的更为常见。这一结果为从微观角度理解闪烁提供了重要的实验数据。更一般地说，我们的方法为分析量子发射体荧光中的微秒级开关动力学提供了一种简单策略。
