Core–shell titanium dioxide–titanium nitride nanotube arrays with near-infrared plasmon resonances

Abstract

Titanium nitride (TiN) is a ceramic with high electrical conductivity which in nanoparticle form, exhibits localized surface plasmon resonances (LSPRs) in the visible region of the solar spectrum. The ceramic nature of TiN coupled with its dielectric loss factor being comparable to that of gold, render it attractive for CMOS polarizers, refractory plasmonics, surface-enhanced Raman scattering and a whole host of sensing applications. We report core-shell TiO-TiN nanotube arrays exhibiting LSPR peaks in the range 775-830 nm achieved by a simple, solution-based, low cost, large area-compatible fabrication route that does not involve laser-writing or lithography. Self-organized, highly ordered TiO nanotube arrays were grown by electrochemical anodization of Ti thin films on fluorine-doped tin oxide-coated glass substrates and then conformally coated with a thin layer of TiN using atomic layer deposition. The effects of varying the TiN layer thickness and thermal annealing on the LSPR profiles were also investigated. Modeling the TiO-TiN core-shell nanotube structure using two different approaches, one employing effective medium approximations coupled with Fresnel coefficients, resulted in calculated optical spectra that closely matched the experimentally measured spectra. Modeling provided the insight that the observed near-infrared resonance was not collective in nature, and was mainly attributable to the longitudinal resonance of annular nanotube-like TiN particles redshifted due to the presence of the higher permittivity TiO matrix. The resulting TiO-TiN core-shell nanotube structures also function as visible light responsive photocatalysts, as evidenced by their photoelectrochemical water-splitting performance under light emitting diode illumination using 400, 430 and 500 nm photons.

Solution-Processed TiO2-Based Schottky Diodes With a Large Barrier Height

“…Compared to these methods, anodization is one of the most promising techniques, because it is simple, fast, suitable for large-area electronics and does not need vacuum technologies [17]. Most studies of TiO2-based Schottky diodes fabricated by anodization so far focused on porous or nanotube structures to obtain highly active surface and high surface to volume ratio [18]- [20].…”

Hot Electrons in TiO2–Noble Metal Nano-Heterojunctions: Fundamental Science and Applications in Photocatalysis

“…Over the recent decade, semiconductor photocatalysts have become highly popular as the key artificial photosynthetic technology and have set the basis for research in the field of photocatalysis. Researchers have developed many semiconductors as suitable candidates for photocatalysts including metal oxides, metal chalcogenides, metal nitrides, bismuth oxyhalides, carbon nitrides, and III-V compounds [ 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 ]. Semiconductor photocatalysts absorb photons to generate active electrons and holes that are then utilized to initiate chemical reduction and oxidation reactions [ 26 , 27 , 28 ].…”

“…Efforts have also been made to modulate the LSPR behavior of noble metals via exotic morphologies [ 98 ]. Atomistic and continuum calculations have provided deeper understanding of the plasmonic responses of these noble metals, and recent efforts have also focused on the use of phase and compositional changes to help evoke plasmon responses in lower cost, non-plasmonic noble metals, transition metal oxides and nitrides, and chalcogenide compounds [ 21 , 99 , 100 , 101 , 102 , 103 ].…”

Ultra-Wideband and Wide-Angle Perfect Solar Energy Absorber Based on Titanium and Silicon Dioxide Colloidal Nanoarray Structure

“…Titanium (Ti) is one of the metal materials commonly used in solar energy absorbers [27]. Thanks to the dielectric property, Ti possesses a strong plasmon resonance performance and has broad-spectrum absorption characteristics [28][29][30]. Additionally, the reserve of Ti is more abundant than traditional noble metals such as gold and silver in the natural world, meaning a low cost.…”