Design and optimization of plasmonic-based metal-dielectric nanocomposite materials for energy applications

TL;DR

This paper models and optimizes plasmonic nanocomposite materials embedded in dielectrics to enhance light absorption for energy applications like solar harvesting and sensing, using a mixing approach for different metal-dielectric combinations.

Contribution

It extends the mixing approach to new dielectric materials and metal combinations, enabling the design of nanocomposites with tailored broadband or multi-peak plasmonic absorption.

Findings

Optimized nanocomposite configurations for broadband solar absorption.

Demonstrated strong multiple plasmonic peaks in designed materials.

Applicable to solar energy harvesting and spectral sensing.

Abstract

Metallic nanoparticles embedded in dielectrics permit enhanced capture of light at specific wavelengths through excitation of plasmons, i.e. the quanta of coherent and collective oscillations of large concentrations of nearly free electrons. In order to maximize the potential of such enhanced absorption in useful tasks, such as the generation of carriers in photocatalysts and semiconductors, it is important to be able to predict and design plasmonic nanocomposites with desired wavelength-dependent optical absorption. Recently, a mixing approach formulated by Garcia and co-workers [Phys. Rev. B, 75, 045439 (2007)] has been successfully applied to model the experimentally measured broadband optical absorption for ternary nanocomposites containing alloys or mixtures of two metals (from Ag, Au or Cu) in SiO dielectric. In this work we present the broadband optical behavior of important optical coating dielectrics (SiN and SiO) and photocatalyst (TiO) containing various configuration of nanoparticles of Al, Au, Ag, or Cu. The spectral behavior of various combinations of the metallic species in the dielectrics was optimized to show either broadband solar absorption or strong multiple plasmonic absorption peaks. The applications of such nanocomposite materials in solar energy harvesting and spectral sensing are also presented and discussed.