Titanium oxynitride thin films with tuneable double epsilon-near-zero behaviour for nanophotonic applications
File(s)1703.09467v1.pdf (772.66 KB)
Accepted version
Author(s)
Type
Journal Article
Abstract
Titanium oxynitride (TiOxNy) thin films are fabricated using reactive magnetron sputtering. The mechanism of their growth formation is explained, and their optical properties are presented. The films grown when the level of residual oxygen in the background vacuum was between 5 nTorr to 20 nTorr exhibit double epsilon-near-Zero (2-ENZ) behavior with ENZ1 and ENZ2 wavelengths tunable in the 700–850 and 1100–1350 nm spectral ranges, respectively. Samples fabricated when the level of residual oxygen in the background vacuum was above 2 × 10–8 Torr exhibit nonmetallic behavior, while the layers deposited when the level of residual oxygen in the background vacuum was below 5 × 10–9 Torr show metallic behavior with a single ENZ value. The double ENZ phenomenon is related to the level of residual oxygen in the background vacuum and is attributed to the mixture of TiN and TiOxNy and TiOx phases in the films. Varying the partial pressure of nitrogen during the deposition can further control the amount of TiN, TiOx, and TiOxNy compounds in the films and, therefore, tune the screened plasma wavelengths. A good approximation of the ellipsometric behavior is achieved with Maxwell–Garnett theory for a composite film formed by a mixture of TiO2 and TiN phases suggesting that double ENZ TiOxNy films are formed by inclusions of TiN within a TiO2 matrix. These oxynitride compounds could be considered as new materials exhibiting double ENZ in the visible and near-IR spectral ranges. Materials with ENZ properties are advantageous for designing the enhanced nonlinear optical response, metasurfaces, and nonreciprocal behavior.
Date Issued
2017-08-18
Date Acceptance
2017-08-18
Citation
ACS Applied Materials and Interfaces, 2017, 9 (35), pp.29857-29862
ISSN
1944-8244
Publisher
American Chemical Society
Start Page
29857
End Page
29862
Journal / Book Title
ACS Applied Materials and Interfaces
Volume
9
Issue
35
Copyright Statement
© 2017 American Chemical Society. This document is the Accepted Manuscript version of a Published Work that appeared in final form in ACS Applied Materials and Interfaces, after peer review and technical editing by the publisher. To access the final edited and published work see https://dx.doi.org/10.1021/acsami.7b07660
Sponsor
Engineering & Physical Science Research Council (E
The Leverhulme Trust
Engineering & Physical Science Research Council (EPSRC)
Engineering & Physical Science Research Council (E
Technology Strategy Board
Engineering & Physical Science Research Council (EPSRC)
Engineering & Physical Science Research Council (E
Grant Number
EP/F012403/1
F/07 058AL
EP/G031819/1
EP/H000917/1
TP/8/MAT/6/I/Q1527C
EP/M020398/1
EP/M013812/1
Subjects
Science & Technology
Technology
Nanoscience & Nanotechnology
Materials Science, Multidisciplinary
Science & Technology - Other Topics
Materials Science
plasmonics
titanium nitride
titanium oxynitride
thin films
epsilon near zero
nonlinear photonics
ALTERNATIVE PLASMONIC MATERIALS
RAY PHOTOELECTRON-SPECTROSCOPY
NITRIDE
METAMATERIALS
TIN
NONLINEARITY
WAVELENGTHS
COATINGS
GROWTH
OXIDES
cond-mat.mtrl-sci
0904 Chemical Engineering
0303 Macromolecular And Materials Chemistry
0306 Physical Chemistry (Incl. Structural)
Publication Status
Published