Excitation of surface plasmons at a SiO2/Ag interface by silicon quantum dots: Experiment and theory
Excitation of surface plasmons at a SiO2/Ag interface by silicon quantum dots: Experiment and theory
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硅量子点在 SiO2/Ag 界面激发表面等离子体：实验与理论
DOI：
10.1103/physrevb.73.075317
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发表时间：
2006
影响因子：
3.7
通讯作者：
A. Polman
中科院分区：
文献类型：
--
作者：
J. Kalkman;H. Gersen;L. Kuipers;A. Polman
通过实验和理论研究了位于 Ag 界面附近的光激发硅量子点 QD 对不同 QD 界面分离的表面等离子体 SP 的激发。通过Si离子注入和热退火在SiO2衬底的近表面区域中形成Si QD。对于具有和不具有银覆盖层的样品，确定了由测量的衰减迹线的拉普拉斯逆变换导出的光致发光衰减率分布。对于最小的、所研究的 Si-QD 到界面距离为 44 nm 的情况，由于 Ag-玻璃界面相对于空气-玻璃界面而言更接近，因此在 =750 nm 处的平均衰减率提高了 80%。基于经典偶极子振荡器模型的计算表明，观察到的衰减率增强主要是由于 SiO2/Ag 界面上的表面等离子体激元的激发。通过将模型计算与实验数据进行比较，确定Si量子点具有高达77±17%的内发射量子效率。在此距离处，它们可以以 1.1±0.210 4 s 1 的速率激发表面等离子体激元。从模型中还可以预测，通过使用金属薄膜，可以进一步增强 Si QD 对表面等离子体的激发。研究发现 Si QD 优先激发对称薄膜表面等离子体。
The excitation of surface plasmons SPs by optically excited silicon quantum dots QDs located near a Ag interface is studied both experimentally and theoretically for different QD-interface separations. The Si QDs are formed in the near-surface region of an SiO2 substrate by Si ion implantation and thermal annealing. Photoluminescence decay-rate distributions, as derived from an inverse Laplace transform of the measured decay trace, are determined for samples with and without a Ag cover layer. For the smallest, investigated Si-QDs-to-interface distance of 44 nm the average decay rate at =750 nm is enhanced by 80% due to the proximity of the Ag-glass interface, with respect to an air-glass interface. Calculations based on a classical dipole oscillator model show that the observed decay rate enhancement is mainly due to the excitation of surface plasmons that are on the SiO2/Ag interface. By comparing the model calculations to the experimental data, it is determined that Si QDs have a very high internal emission quantum efficiency of 77±17%. At this distance they can excite surface plasmons at a rate of 1.1±0.210 4 s 1 . From the model it is also predicted that by using thin metal films the excitation of surface plasmons by Si QDs can be further enhanced. Si QDs are found to preferentially excite symmetric thin-film surface plasmons.
影响因子：
41.2
作者：
Okamoto, K;Niki, I;Scherer, A
通讯作者：
Scherer, A