Title: The Interplay of Shape and Crystalline Anisotropies in Plasmonic Semiconductor Nanocrystals

Abstract

Doped semiconductor nanocrystals are an emerging class of materials hosting localized surface plasmon resonance (LSPR) over a wide optical range. Studies so far have focused on tuning LSPR frequency by controlling the dopant and carrier concentrations in diverse semiconductor materials. However, the influence of anisotropic nanocrystal shape and of intrinsic crystal structure on LSPR remain poorly explored. Here, we illustrate how these two factors collaborate to determine LSPR characteristics in hexagonal cesium-doped tungsten oxide nanocrystals. The effect of shape anisotropy is systematically analyzed via synthetic control of nanocrystal aspect ratio (AR), from disks to nanorods. We demonstrate the dominant influence of crystalline anisotropy, which uniquely causes strong LSPR band-splitting into two distinct peaks with comparable intensities. Modeling typically used to rationalize particle shape effects is refined by taking into account the anisotropic dielectric function due to crystalline anisotropy, thus fully accounting for the AR-dependent evolution of multiband LSPR spectra. Furthermore, this new insight into LSPR of semiconductor nanocrystals provides a novel strategy for an exquisite tuning of LSPR line shape.

Authors:

Kim, Jongwook ^[1]; Agrawal, Ankit ^[1]; Krieg, Franziska ^[2]; Bergerud, Amy ^[3]; Milliron, Delia J. ^[1]

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+ Show Author Affiliations

1. McKetta Department of Chemical Engineering, University of Texas at Austin, Austin, Texas 78712, United States
2. McKetta Department of Chemical Engineering, University of Texas at Austin, Austin, Texas 78712, United States, Institute of Inorganic Chemistry, Department of Chemistry and Applied Biosciences, ETH Zurich, Vladimir-Prelog-Weg 1, 8093 Zurich, Switzerland, Empa-Swiss Federal Laboratories for Materials Science and Technology, Uberlandstrasse 129, 8600, Dubendorf, Switzerland
3. McKetta Department of Chemical Engineering, University of Texas at Austin, Austin, Texas 78712, United States, Department of Materials Science & Engineering, University of California, Berkeley, Berkeley, California 94720, United States

Publication Date:

Mon May 16 00:00:00 EDT 2016

Research Org.:

Univ. of Texas, Austin, TX (United States)

Sponsoring Org.:

USDOE Advanced Research Projects Agency - Energy (ARPA-E); USDOE Office of Energy Efficiency and Renewable Energy (EERE)

Contributing Org.:

SIBR

OSTI Identifier:

1253218

Alternate Identifier(s):

OSTI ID: 1258027

Grant/Contract Number:  

AR0000489

Resource Type:

Published Article

Journal Name:

Nano Letters

Additional Journal Information:

Journal Name: Nano Letters Journal Volume: 16 Journal Issue: 6; Journal ID: ISSN 1530-6984

Publisher:

American Chemical Society

Country of Publication:

United States

Language:

English

Subject:

77 NANOSCIENCE AND NANOTECHNOLOGY; doped semiconductor; tungsten bronze; nanorod; platelet; metal oxide