title: Densely packed aluminum-silver nanohelices as an ultra-thin perfect light absorber.
abstract: Metals have been formed into nanostructures to absorb light with high efficiency through surface plasmon resonances. An ultra-thin plasmonic structure that exhibits strong absorption over wide ranges of wavelengths and angles of incidence is sought. In this work, a nearly perfect plasmonic nanostructure is fabricated using glancing angle deposition. The difference between the morphologies of obliquely deposited aluminum and silver nanohelices is exploited to form a novel three-dimensional structure, which is an aluminum-silver nanohelix array on a pattern-free substrate. With a thickness of only 470 nm, densely distributed nanohelices support rod-to-rod localized surface plasmons for broadband and polarization-independent light extinction. The extinctance remains high over wavelengths from 400 nm to 2000 nm and angles of incidence from 0° to 70°.
authors.affiliation: Department of Electro-Optical Engineering, National Taipei University of Technology, No. 1, Sec. 3, Chung-Hsiao E. Rd. Taipei, (106) Taiwan.
authors.forename: Yi-Jun
authors.initials: YJ
authors.lastname: Jen
authors.affiliation: Department of Electro-Optical Engineering, National Taipei University of Technology, No. 1, Sec. 3, Chung-Hsiao E. Rd. Taipei, (106) Taiwan.
authors.forename: Yu-Jie
authors.initials: YJ
authors.lastname: Huang
authors.affiliation: Department of Electro-Optical Engineering, National Taipei University of Technology, No. 1, Sec. 3, Chung-Hsiao E. Rd. Taipei, (106) Taiwan.
authors.forename: Wei-Chih
authors.initials: WC
authors.lastname: Liu
authors.affiliation: Department of Electro-Optical Engineering, National Taipei University of Technology, No. 1, Sec. 3, Chung-Hsiao E. Rd. Taipei, (106) Taiwan.
authors.forename: Yueh Weng
authors.initials: YW
authors.lastname: Lin