Excitation of surface plasmons at a SiO2/Ag interface by silicon quantum dots: Experiment and theory

Kalkman, J. and Gersen, H. and Kuipers, L. and Polman, A. (2006) Excitation of surface plasmons at a SiO2/Ag interface by silicon quantum dots: Experiment and theory. Physical Review B: Condensed matter and materials physics, 73 (7). 075317. ISSN 1098-0121

Preview

PDF
370Kb

Abstract:	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 lambda=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±0.2)×104 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.
Item Type:	Article
Copyright:	© 2006 The American Physical Society
Research Group:	Optical Sciences (OS)
Link to this item:	http://purl.utwente.nl/publications/57566
Official URL:	http://dx.doi.org/10.1103/PhysRevB.73.075317
Export this item as:	BibTeX EndNote HTML Citation Reference Manager

Show download statistics for this publication

Repository Staff Only: item control page

Metis ID: 231034