Model of Fluorescence Intermittency of Single Colloidal Semiconductor Quantum Dots Using Multiple Recombination Centers
Model of Fluorescence Intermittency of Single Colloidal Semiconductor Quantum Dots Using Multiple Recombination Centers
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DOI：
10.1103/physrevlett.103.207402
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发表时间：
2009-11-13
影响因子：
8.6
通讯作者：
Janko, Boldizsar
中科院分区：
文献类型：
--
作者：
Frantsuzov, Pavel A.;Volkan-Kacso, Sandor;Janko, Boldizsar
我们提出了一个新的物理模型，解决了单个胶体量子点荧光中闪烁时间的幂律分布的长期谜团。该模型考虑了激子通过多个复合中心的非辐射弛豫。每个中心被允许在两个准稳定状态之间切换。我们指出，传统的阈值分析方法用于提取开、关时间分布的指数有一个严重的缺陷：分布的定性性质强烈依赖于分离开、关状态所选择的阈值。我们的新模型自然地解释了这种阈值依赖性，以及单量子点荧光轨迹的其他关键实验特征，如幂律功率谱（1/f噪声）。
We present a new physical model resolving a long-standing mystery of the power-law distributions of the blinking times in single colloidal quantum dot fluorescence. The model considers the nonradiative relaxation of the exciton through multiple recombination centers. Each center is allowed to switch between two quasistationary states. We point out that the conventional threshold analysis method used to extract the exponents of the distributions for the on times and off times has a serious flaw: the qualitative properties of the distributions strongly depend on the threshold value chosen for separating the on and off states. Our new model explains naturally this threshold dependence, as well as other key experimental features of the single quantum dot fluorescence trajectories, such as the power-law power spectrum (1/f noise).