Enhanced generation and anisotropic Coulomb scattering of hot electrons in an ultra-broadband plasmonic nanopatch metasurface [electronic resource]

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Bibliographic Details
Online Access: Full Text (via OSTI)
Corporate Author: Argonne National Laboratory (Researcher)
Format: Government Document Electronic eBook
Language:English
Published: Arlington, Va. : Oak Ridge, Tenn. : United States. Air Force. Office of Scientific Research ; distributed by the Office of Scientific and Technical Information, U.S. Department of Energy, 2017.
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Abstract:The creation of energetic electrons through plasmon excitation of nanostructures before thermalization has been proposed for a wide number of applications in optical energy conversion and ultrafast nanophotonics. However, the use of "nonthermal" electrons is primarily limited by both a low generation efficiency and their ultrafast decay. We report experimental and theoretical results on the use of broadband plasmonic nanopatch metasurfaces comprising a gold substrate coupled to silver nanocubes that produce large concentrations of hot electrons, which we measure using transient absorption spectroscopy. We find evidence for three subpopulations of nonthermal carriers which we propose arise from anisotropic electron-electron scattering within sp-bands near the Fermi surface. The bimetallic character of the metasurface strongly impacts the physics, with dissipation occurring primarily in the gold whereas the quantum process of hot electron generation takes place in both components. As a result, our calculations show that the choice of geometry and materials is crucial for producing strong ultrafast nonthermal electron components.
Item Description:Published through SciTech Connect.
10/17/2017.
"136639"
Nature Communications 8 1 ISSN 2041-1723 AM.
Matthew E. Sykes; Jon W. Stewart; Gleb M. Akselrod; Xiang -Tian Kong; Zhiming Wang; David J. Gosztola; Alex B. F. Martinson; Daniel Rosenmann; Maiken H. Mikkelsen; Alexander O. Govorov; Gary P. Wiederrecht.
Argonne-Northwestern Solar Energy Research (ANSER)
Physical Description:Article No. 986 : digital, PDF file.