Authors
|
Kilic, U. ; Mock, A. ; Feder, R. ; Sekora, D. ; Hilfiker, M. ; Korlacki, R. ; Schubert, E. ; Argyropoulos, C. ; Schubert, M.
|
Title
|
Tunable plasmonic resonances in Si-Au slanted columnar heterostructure thin films
|
Date
|
19.06.2019
|
Number
|
56823
|
Abstract
|
We report on fabrication of spatially-coherent columnar plasmonic nanostructure superlattice-type thin films with high porosity and strong optical anisotropy using glancing angle deposition. Subsequent and repeated depositions of silicon and gold lead to nanometer-dimension subcolumns with controlled lengths. We perform generalized spectroscopic ellipsometry measurements and finite element method computations to elucidate the strongly anisotropic optical properties of the highly-porous Si-Au slanted columnar heterostructures. The occurrence of a strongly localized plasmonic mode with displacement pattern reminiscent of a dark quadrupole mode is observed in the vicinity of the gold subcolumns. We demonstrate tuning of this quadrupole-like mode frequency within the near-infrared spectral range by varying the geometry of Si-Au slanted columnar heterostructures. In addition, coupled-plasmon-like and inter-band transition-like modes occur in the visible and ultra-violet spectral regions, respectively. We elucidate an example for the potential use of Si-Au slanted columnar heterostructures as a highly porous plasmonic sensor with optical read out sensitivity to few parts-per-million solvent levels in water.
|
Publisher
|
Scientific Reports
|
Wikidata
|
|
Citation
|
Scientific Reports 9 (2019) ID 71
|
DOI
|
https://doi.org/10.1038/S41598-018-37153-X
|
Tags
|
|