Open AccessBroadband infrared metamaterial absorber with visible transparency using ITO as ground plane
Author(s) -
Govind Dayal,
S. Anantha Ramakrishna
Publication year - 2014
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.22.015104
Subject(s) - materials science , ground plane , dielectric , optoelectronics , indium tin oxide , optics , metamaterial , plasmon , metamaterial absorber , infrared , permittivity , layer (electronics) , nanotechnology , telecommunications , physics , tunable metamaterials , computer science , antenna (radio)
Metamaterials that have broadband absorption at MIR frequencies, and yet, are transmitive at visible frequencies are fabricated using a semi-conducting Indium Tin Oxide (ITO) film as ground plane. The metamaterial absorber consists of an array of uniform aluminum disks separated by a Zinc Sulphide (ZnS) dielectric spacer layer from the ITO ground plane. The metamaterial was fabricated by a simple, cost-effective vapor deposition through a shadow mask. Compared with the usual metal/dielectric/metal tri-layer absorbers, the metal/dielectric/ITO absorber shows a peak absorbance of 98% and >70% over the mid-infrared regime from 4 to 7 μm. The broadband nature arises due to smaller dispersion in the dielectric permittivity of ITO compared to that of plasmonic metals at mid-infrared frequencies.