Institut Lumière-Matière, CNRS UMR5306, Université Lyon 1, Université de Lyon , 69622 Villeurbanne CEDEX, France.
ACS Nano. 2015 Jan 27;9(1):886-93. doi: 10.1021/nn506598t. Epub 2015 Jan 8.
We present an unbiased and robust analysis method for power-law blinking statistics in the photoluminescence of single nanoemitters, allowing us to extract both the bright- and dark-state power-law exponents from the emitters' intensity autocorrelation functions. As opposed to the widely used threshold method, our technique therefore does not require discriminating the emission levels of bright and dark states in the experimental intensity timetraces. We rely on the simultaneous recording of 450 emission timetraces of single CdSe/CdS core/shell quantum dots at a frame rate of 250 Hz with single photon sensitivity. Under these conditions, our approach can determine ON and OFF power-law exponents with a precision of 3% from a comparison to numerical simulations, even for shot-noise-dominated emission signals with an average intensity below 1 photon per frame and per quantum dot. These capabilities pave the way for the unbiased, threshold-free determination of blinking power-law exponents at the microsecond time scale.
我们提出了一种公正且稳健的分析方法，用于研究单纳发射器中光致发光的幂律闪烁统计，从而能够从发射器的强度自相关函数中提取亮态和暗态的幂律指数。与广泛使用的阈值方法不同，我们的技术因此不需要在实验强度时间轨迹中区分亮态和暗态的发射水平。我们依赖于以 250 Hz 的帧率同时记录 450 个单个 CdSe/CdS 核/壳量子点的发射时间轨迹，具有单光子灵敏度。在这些条件下，即使对于平均强度低于每个帧和每个量子点 1 个光子的具有噪声主导的发射信号，我们的方法也可以通过与数值模拟进行比较，以 3%的精度确定 ON 和 OFF 的幂律指数。这些功能为在微秒时间尺度上进行无偏差、无阈值的闪烁幂律指数确定铺平了道路。
