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arXiv 0808.3191physics.optics
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通过控制局域态密度确定CdSe量子点的尺寸依赖振子强度和量子效率

Size dependent oscillator strength and quantum efficiency of CdSe quantum dots determined by controlling the local density of states

M. D. Leistikow, J. Johansen, A. J. Kettelarij, P. Lodahl, W. L. Vos

摘要:

我们实验研究了在受控局域态密度(LDOS)环境中CdSe量子点的时间分辨发射。衰减率是相对于频率测量的,并且是到镜子的距离的函数。我们观察到的衰减率和LDOS之间的线性关系,使我们能够确定的尺寸依赖的量子效率和振子强度。我们发现量子效率随发射能量的增加而降低,主要是由于非辐射衰减的增加。首次得到了这类重要的量子点的振子强度。振子强度随频率的变化很弱,这与量子点在强约束极限下的行为一致。令人惊讶的是,测量的绝对值比理论计算值低5倍。我们的研究结果对于CdSe量子点在自发发射控制和腔量子电动力学中的应用具有重要意义。

英文摘要:

We study experimentally time-resolved emission of CdSe quantum dots in an environment with a controlled local density of states (LDOS). The decay rate is measured versus frequency and as a function of distance to a mirror. We observe a linear relation between the decay rate and the LDOS, allowing us to determine the size-dependent quantum efficiency and oscillator strength. We find that the quantum efficiency decreases with increasing emission energy mostly due to an increase in nonradiative decay. For the first time, we manage to obtain the oscillator strength of the important class of CdSe quantum dots. The oscillator strength varies weakly with frequency in agreement with behavior of quantum dots in the strong confinement limit. Surprisingly, the measured absolute values are a factor of 5 below theoretically calculated values. Our results are relevant for applications of CdSe quantum dots in spontaneous emission control and cavity quantum electrodynamics.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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