ITO–TiN–ITO Sandwiches for Near-Infrared Plasmonic Materials

Abstract

Indium tin oxide (ITO)-based sandwich structures with the insertion of ultrathin (<10 nm) titanium nitride (TiN) are investigated as near-infrared (NIR) plasmonic materials. The structural, electrical, and optical properties reveal the improvement of the sandwich structures stemmed from TiN insertion. TiN is a well-established alternative to noble metals such as gold, elevating the electron conductivity of sandwich structures as its thickness increases. Dielectric permittivities of TiN and top ITO layers show TiN-thickness-dependent properties, which lead to moderate and tunable effective permittivities for the sandwiches. The surface plasmon polaritons (SPP) of the ITO-TiN-ITO sandwich at the telecommunication window (1480-1570 nm) are activated by prism coupling using Kretschmann configuration. Compared with pure ITO films or sandwiches with metal insertion, the reflectivity dip for sandwiches with TiN is relatively deeper and wider, indicating the enhanced coupling ability in plasmonic materials for telecommunications. The SPP spatial profile, penetration depth, and degree of confinement, as well as the quality factors, demonstrate the applicability of such sandwiches for NIR plasmonic materials in various devices.

Review of Experimental Setups for Plasmonic Photocatalytic Reactions

“…For future advanced applications in plasmonic photocatalytic reactions, a fabrication method that provides samples with stronger plasmon coupling and induction may induce a new breakthrough in plasmonic photocatalytic studies. Layered structures for creating plasmonic black absorber [93] and TiN materials for metal-like near-infrared plasmonics responses [177][178][179][180][181][182] are potential materials in relevant applications. Nanoparticles of various sizes and shapes [183,184] can achieve various plasmon modes for the target light absorption band.…”

Transparent Conductive Oxides and Their Applications in Near Infrared Plasmonics

“…Accordingly, the niche application of TCOs as NIR plasmonic materials requires the introduction of noble metals, to improve their overall performance. Our previous work shows sandwich structures as ITO/Au/ITO (Figure a) and ITO/TiN/ITO (Figure b) will significantly improve ITO's conductivity. Table lists the various ITO composites and related measurements we performed to tune the electronic properties of ITO.…”

“…TEM cross‐section view of (a) ITO/Au(2.4 nm)/ITO sandwich structure and (b) ITO/TiN(9 nm)/ITO sandwich structure. a,b) Reproduced with permission . Copyright 2018, American Chemical Society.…”

“…Nobel metals are widely used as surface plasmon materials because of their advantages including long propagation length of SP mode, low penetrating depth into metals, large near‐field enhancement, and wide applicable wavelength range (from visible to mid‐infrared region) . But in NIR range, TCOs could outperform metals with some virtues: The manufacturing process of TCOs is compatible with CMOS technology, high quality TCOs thin films can be readily fabricated by processes of chemical vapor deposition (CVD), physical vapor deposition (PVD), magnetron sputtering, etc. The optical losses of TCOs are less than metals and their optical properties are can be tuned over a wide range by adjusting the composition.…”

TiN-based organic-inorganic composite films with dual functions of solar control and low-emission for energy-saving coatings

“…However, such multilayer films are complex and high-cost. Hence, the development of novel energy-saving films, especially single-layer film, with dual functions of solar control and low-emission that can be used for both hot summer and cold winter areas is highly urgent [8][9][10].…”