Trapping time statistics and efficiency of transport of optical excitations in dendrimers.
Trapping time statistics and efficiency of transport of optical excitations in dendrimers.
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DOI：
10.1063/1.1778136
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发表时间：
2004-03
期刊：
影响因子：
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通讯作者：
D. Heijs;V. Malyshev;J. Knoester
中科院分区：
文献类型：
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作者：
D. Heijs;V. Malyshev;J. Knoester
我们从理论上研究了树枝状体系中的俘获时间分布和激发能输运效率。在树枝状聚合物的外围处产生的激发在位于其核心处的陷阱上的捕获被用作跨树枝状聚合物的能量传输效率的探针。运输过程被视为最近邻的树枝状大分子单元之间的激发的非相干跳跃，并使用速率方程来描述。我们解释了激发在树枝状聚合物中扩散时的辐射和非辐射衰减。我们推导出捕获时间分布和捕获效率的拉普拉斯变换的精确表达式，并分析了能量偏差，树枝状聚合物代数以及衰变和跳跃的相对速率的各种实现。我们表明，支配的捕获效率的基本参数是现场激发衰变率和捕获时间（平均第一次通过时间）在没有衰变的情况下的产品。
We theoretically study the trapping time distribution and the efficiency of the excitation energy transport in dendritic systems. Trapping of excitations, created at the periphery of the dendrimer, on a trap located at its core, is used as a probe of the efficiency of the energy transport across the dendrimer. The transport process is treated as incoherent hopping of excitations between nearest-neighbor dendrimer units and is described using a rate equation. We account for radiative and nonradiative decay of the excitations while diffusing across the dendrimer. We derive exact expressions for the Laplace transform of the trapping time distribution and the efficiency of trapping, and analyze those for various realizations of the energy bias, number of dendrimer generations, and relative rates for decay and hopping. We show that the essential parameter that governs the trapping efficiency is the product of the on-site excitation decay rate and the trapping time (mean first passage time) in the absence of decay.