Absorption enhancement due to scattering by dipoles into silicon waveguides

Date

2006-08-22

Authors

Catchpole, Kylie
Pillai, S.

Journal Title

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Volume Title

Publisher

American Institute of Physics (AIP)

Abstract

We develop an optical model for absorption enhancement and diffuse reflectance by metal nanoparticles on a siliconwaveguide. A point dipole treatment is used, including the effects of the waveguide on both the angular emission spectrum and scattering cross section of the dipoles. The model agrees very well with our experimental results of greatly enhanced electroluminescence and photocurrent from silicon-on-insulator light-emitting diodes and also gives very good agreement with previously reported diffuse reflectance measurements. The results suggest that the main mechanism in the enhancement of diffuse reflectance in this system is a dramatic enhancement in the scattering cross section of waveguided light, rather than a waveguide-mediated dipole-dipole interaction. We also put lower bounds on the radiative efficiency of scattering by the nanoparticles.

Description

Keywords

Electroluminescence, Light absorption, Light scattering, Nanostructured materials, Photocurrents, Semiconducting silicon, Diffuse reflectance measurements, Dipole-dipole interaction, Metal nanoparticles, Silicon waveguides, Optical waveguides

Citation

Source

Journal of Applied Physics

Type

Journal article

Book Title

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DOI

10.1063/1.2226334

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