Refractory Titanium Nitride Research Articles

Optical Heating Controlled With a Thermoplasmonic Metasurface

We develop a photothermal technology to control optical heating of polymer and liquid crystal films through a refractory titanium nitride (TiN) metasurface. The metasurface represents an array of identical square-shaped TiN nanoantennas on a Si substrate. Upon CW laser illumination, a TiN nanoantenna experiences anomalous Joule heating at a plasmon resonance. A temperature rise provides a unique opportunity for locally probing phase transitions. In the case of heterogeneous PMMA thin films or polymeric blends, a controlled optical heating is needed to probe the glass transition temperature (Tg) of their constituents. Here, we model a controlled thermal response originating from the TiN nanoantenna under CW laser illumination by using FDTD/FEM methods.

Broadband Absorption Based on Thin Refractory Titanium Nitride Patterned Film Metasurface.

In this paper, a thin metasurface perfect absorber based on refractory titanium nitride (TiN) is proposed. The size parameter of the metasurface is investigated based on the finite difference time domain method and transfer matrix method. With only a 15-nm-thick TiN layer inside the silica/TiN/silica stacks standing on the TiN substrate, the near-perfect absorption throughout the visible regime is realized. The cross-talk between the upper and lower dielectric layers enables the broadening of the absorption peak. After patterning the thin film into a nanodisk array, the resonances from the nanodisk array emerge to broaden the high absorption bandwidth. As a result, the proposed metasurface achieves perfect absorption in the waveband from 400 to 2000 nm with an average absorption of 95% and polarization-insensitivity under the normal incidence. The proposed metasurface maintains average absorbance of 90% up to 50-degree oblique incidence for unpolarized light. Our work shows promising potential in the application of solar energy harvesting and other applications requiring refractory metasurfaces.

Scalable wavelength-selective solar absorber based on refractory TiN nanostructures

Scalable wavelength-selective solar absorbers with both high selectivity and thermostability are desired for efficient utilization of solar thermal energy. In this study, we present a refractory titanium nitride (TiN) moth-eye-like nanostructure, fabricated via oblique deposition, that provides high solar-light absorptivity (0.9) and low emissivity (0.17) at 100 °C under atmospheric conditions. The strong visible-light absorption of the structure is complemented by a Fabry−Pérot resonance that broadens the strong absorption band into the near-infrared light region for certain structure dimensions. In addition, TiN is a promising material, due to its refractory nature, having a very high melting point of 2930 °C. The oblique deposition method used to obtain the nano-structured TiN does not require the use of lithographic techniques or expensive nano-templates, thus it is suitable for large-scale fabrication. The nanostructure and its fabrication method have significant potential for practical applications requiring efficient use of solar-light energy.

Narrow‐Band Thermal Emitter with Titanium Nitride Thin Film Demonstrating High Temperature Stability

AbstractA refractory wavelength selective thermal emitter is experimentally realized by the excitation of Tamm plasmon polaritons (TPPs) between a titanium nitride (TiN) thin film and a distributed Bragg reflector (DBR). The absorptance reaches nearly unity at ≈3.73 μm with the bandwidth of 0.36 μm in the experiment. High temperature stabilities are confirmed up to 500 and 1000 °C in ambient and in vacuum, respectively. When the TiN TPP structure is compared to the TiN–insulator–TiN (TiN‐metal–insulator–metal (MIM)) structure, the former shows higher Q‐factor, which indicates the advantage of choosing the TiN TTP structure against the MIM structure. The proposed refractory TiN TPP structure is lithography‐free and scalable, which paves a way for large scale thermal emitters in practical usage.

Disordered Nonlinear Metalens for Raman Spectral Nanoimaging.

Over the past decades, considerable progress has been made toward far-field optical imaging beyond the diffraction limit. However, most working proof-of-concepts are based on either time-consuming scanning of a subdiffraction focal spot over a sample or postrecovery treatment using a priori information on a sought image. To our knowledge, none of these can be regarded as being close to a perfect far-field superlensing system capable of real-time color imaging with subwavelength resolution. In this paper, we suggest a proof-of-concept for far-field nonlinear metalens that is made of a disordered metal-dielectric nanocomposite. Postoxidation of a refractory titanium nitride (TiN) thin film, used as a nonlinear plasmonic material, results in the formation of a titanium oxynitride (TiON) film comprising a mixture of multiple phases of TiOxNy. Due to a double epsilon-near-zero behavior near the percolation threshold, the TiON favors supercoupling of the incident light to surface plasmon resonance within the visible and near-infrared range. Point spread function narrowing is achieved owing to the multiplicative nature of stimulated Raman scattering (SRS) and enhanced third-order optical nonlinearity in TiN and TiO2 particle chains through plasmon resonances and Anderson localization of light, respectively. Combined with a conventional confocal optical microscope, the multimode metalens shows subwavelength resolution of λ/6NA at different visible wavelengths (SRS overtones) using multiwalled carbon nanotubes as a test sample. We are confident that our finding will bring us one step closer to developing a robust and versatile far-field super-resolution color imaging system and, eventually, implementing "eye-on-a-chip" technology.

Ultra-broadband perfect solar absorber by an ultra-thin refractory titanium nitride meta-surface

Electromagnetic wave absorbers with thinner structural thickness but with broader spectral absorption bandwidth are more desirable for various applications in solar energy and optoelectronics. In this work, a refractory titanium nitride meta-surface with efficient, ultra-broadband solar energy absorption is theoretically designed and numerically demonstrated. The resulting 250-nm-thick meta-surface absorber exhibits an ultra-broadband perfect absorption over the whole ultraviolet-visible-near infrared range. With taking the A > 90% into account, the absorption bandwidth is up to 1110nm with the wavelength range varied from 0.316 μm to 1.426 μm. The titanium nitride nano-resonators array and its coating structure of titanium dioxide array cooperatively provide multiple resonant modes, which therefore introduce strong coupling with the solar radiation and eventually produce an ultra-broadband absorption. The absorption spectrum can be feasibly manipulated via tuning the structural parameters. Most importantly, in sharp contrast to the common absorbers formed with metallic nano-resonators, the titanium nitride based solar absorber is with much stronger thermal stability, illustrating the impressive promise for wide applications such as thermo-photovoltaics and other high-power optoelectronic processes.

Refractory titanium nitride two-dimensional structures with extremely narrow surface lattice resonances at telecommunication wavelengths

Regular arrays of plasmonic nanoparticles have brought significant attention over the last decade due to their ability to support localized surface plasmons (LSPs) and exhibit diffractive grating behavior simultaneously. For a specific set of parameters (i.e., period, particle shape, size, and material), it is possible to generate super-narrow surface lattice resonances (SLRs) that are caused by interference of the LSP and the grating Rayleigh anomaly. In this letter, we propose plasmonic structures based on regular 2D arrays of TiN nanodisks to generate high-Q SLRs in an important telecommunication range, which is quite difficult to achieve with conventional plasmonic materials. The position of the SLR peak can be tailored within the whole telecommunication bandwidth (from ≈ 1.26 μm to ≈ 1.62 μm) by varying the lattice period, while the Q-factor is controlled by changing nanodisk sizes. We show that the Q-factor of SLRs can reach a value of 2 × 103, which is the highest reported Q-factor for SLRs at telecommunication wavelengths so far. Tunability of optical properties, refractory behavior, and low-cost fabrication of TiN nanoparticles paves the way for manufacturing cheap nanostructures with extremely stable and adjustable electromagnetic response at telecommunication wavelengths for a large number of applications.

Simulation of perfect absorber at visible frequencies using TiN-based refractory plasmonic metamaterials

Refractory titanium nitride (TiN) nanoellipsoid was proposed as unit component for metamaterial perfect absorber in visible frequencies. Combining both the intrinsic loss of the TiN material in short wavelength ( 500 nm), the metamaterial perfect absorber based TiN nanoellipsoid array can be a broadband perfect absorber in whole visible region. An average absorbance of 98.5 % over the whole visible spectrum was obtained with a total thickness of only 200 nm. The structure is directly applicable to all kinds of opaque substrates with no need for metallic bottom.

DESTRUCTION OF BLADES SURFACE COATING

The article discusses a change of impact elasticity (a crack resistance or other value characterizing a resistance to rupture) depending on the cutting blade heating temperature. The test results showed that high temperature impact resistance strengthening of the hard alloy blade structure by treatment of its surface with wearresistant refractory titanium nitride coating proved its effectiveness at 500 0C and at 600 0C. At temperature of 900 0C a deterioration occurs resulted from generation of defects in the coating and in the hard alloy surface layer which become the sites of destructive impact crack initiation.

Effective third-order nonlinearities in metallic refractory titanium nitride thin films

Nanophotonic devices offer an unprecedented ability to concentrate light into small volumes which can greatly increase nonlinear effects. However, traditional plasmonic materials suffer from low damage thresholds and are not compatible with standard semiconductor technology. Here we study the nonlinear optical properties in the novel refractory plasmonic material titanium nitride using the Z-scan method at 1550 nm and 780 nm. We compare the extracted nonlinear parameters for TiN with previous works on noble metals and note a similarly large nonlinear optical response. However, TiN films have been shown to exhibit a damage threshold up to an order of magnitude higher than gold films of a similar thickness, while also being robust, cost-efficient, bio- and CMOS-compatible. Together, these properties make TiN a promising material for metal-based nonlinear optics.

On the possibility of obtaining refractory metal nitrides in a calciothermic process

The possibility of obtaining refractory titanium nitride TiN in a calciothermic process is shown. The dependence of the combustion rate and temperature on the nitrogen pressure is studied. The phenomenon of super-adiabatic heating during combustion of the Ca-TiO2-N2 system is found.