Wang Yikuan, Yang Tianyu, Pourmand Mahshid, Miller Jacob J, Tuominen Mark T, Achermann Marc
Physics Department, University of Massachusetts Amherst, 666 N. Pleasant Street, Amherst, MA 01003, USA.
Opt Express. 2010 Jul 19;18(15):15560-8. doi: 10.1364/OE.18.015560.
We discuss the coupling between optically excited semiconductor nanocrystals (NC) and thin metal films in both the single and multi-exciton regime. Using time-resolved photoluminescence spectroscopy, we determine the decay dynamics of free space and surface plasmon polariton (SPP) coupled emission. The two dynamics are found to be distinctly different at very small NC-metal separations and at photon energies close to the SPP resonance frequency. A comparison with numerical calculations allow us to conclude that the difference in emission dynamics is associated with the different interactions of parallel and perpendicular dipole emitters with lossy surface waves. Experiments at high excitation densities reveal that the coupling to SPPs and lossy surface waves is identical for excitons and biexcitons.
我们讨论了在单激子和多激子体系中，光激发半导体纳米晶体（NC）与薄金属膜之间的耦合。利用时间分辨光致发光光谱，我们确定了自由空间和表面等离激元极化激元（SPP）耦合发射的衰减动力学。发现在非常小的NC与金属间距以及光子能量接近SPP共振频率时，这两种动力学明显不同。与数值计算的比较使我们能够得出结论，发射动力学的差异与平行和垂直偶极发射体与有损耗表面波的不同相互作用有关。在高激发密度下的实验表明，对于激子和双激子，与SPP和有损耗表面波的耦合是相同的。
