Broadband Absorption Based on Thin Refractory Titanium Nitride Patterned Film Metasurface

Plasmonic group IVB transition metal nitrides: Fabrication methods and applications in biosensing, photovoltaics and photocatalysis

This review paper focuses on group IVB transition metal nitrides (TMNs) such as titanium nitride (TiN), zirconium nitride (ZrN), and hafnium nitride (HfN) and as alternative plasmonic materials to noble metals like gold and silver. It delves into the fabrication methods of these TMNs, particularly emphasizing thin film fabrication techniques like magnetron sputtering and atomic layer deposition, as well as nanostructure fabrication processes applied to these thin films. Overcoming the current fabrication and application-related challenges requires a deep understanding of the material properties, deposition techniques, and application requirements. Here, we discuss the impact of fabrication parameters on the properties of resulting films, highlighting the importance of aligning fabrication methods with practical application requirements for optimal performance. Additionally, we summarize and tabulate the most recent plasmonic applications of these TMNs in fields like biosensing, photovoltaic energy, and photocatalysis, contributing significantly to the current literature by consolidating knowledge on TMNs.

Nanostructures/TiN layer/Al2O3 layer/TiN substrate configuration-based high-performance refractory metasurface solar absorber

Metasurface solar absorber serves as a kind of important component for green energy devices to convert solar electromagnetic waves into thermal energy. In this work, we design a new solar light absorber configuration that incorporates the titanium nitride substrate, aluminum oxide layer, titanium nitride layer, and the topmost refractory nanostructures. The metasurface absorber based on this configuration can achieve an average spectral absorption of over 91% and a total solar radiation absorption of 91.5% at ultra-wide wavelengths of 300-2500 nm. It is discovered that the excellent performance of the proposed metasurface absorber is attributed to the synergistic effects of surface plasmonic effect and Fabry-Pérot (FP) cavity resonance by comprehensive analysis of the simulated field distributions. Furthermore, the effect of geometrical parameter of the proposed configuration on absorber performance is studied, indicating the proposed configuration possesses a large fabrication tolerance. Moreover, the proposed configuration is not sensitive to the polarization direction and the angle of incident light. It is also found that the use of other refractory metal materials and other shapes as the topmost absorbent nanostructures also have good results with this configuration. This work can offer a universal platform for constructing and guiding the design of refractory metasurface solar absorbers.

Visible and Near-Infrared Broadband Absorber Based on Ti3C2Tx MXene-Wu

A high absorption broadband absorber based on MXene and tungsten nanospheres in visible and near-infrared bands is proposed. The absorber has a maximum absorption of 100% and an average absorption of 95% in the wavelength range of 400-2500 nm. The theoretical mechanism and parameter adjustability of the absorber are analyzed by FDTD solutions. The results show that the structural parameters can effectively adjust the absorption performance. The good absorption performance is due to the action of the local surface plasmon resonance coupling with the gap surface plasmon resonance and Fabry-Perot resonance. The simulation results show that the absorber is insensitive to the polarization and oblique incidence angle of incident light, and that high absorption and broadband can be maintained when the oblique incidence angle is up to 60°.

Nanostructures for Photonics and Optoelectronics

As microelectronic technology approaches the limit of what can be achieved in terms of speed and integration level, there is an increasing interest in moving from electronics to photonics, where photons and light beams replace electrons and electrical currents, which will result in higher processing speeds and lower power consumption [...]

Perfect Optical Absorbers by All-Dielectric Photonic Crystal/Metal Heterostructures Due to Optical Tamm State

In this study, we theoretically and experimentally investigated the perfect optical absorptance of a photonic heterostructure composed of a truncated all-dielectric photonic crystal (PC) and a thick metal film in the visible regions. The three simulated structures could achieve narrow-band perfect optical absorption at wavelengths of 500 nm, 600 nm, and 700 nm, respectively. Based on the measured experimental results, the three experimental structures achieved over 90% absorption at wavelengths of 489 nm, 604 nm, and 675 nm, respectively. The experimental results agreed well with the theoretical values. According to electromagnetic field intensity distributions at the absorption wavelengths, the physical mechanism of perfect absorption was derived from the optical Tamm state (OTS). The structure was simple, and the absorption characteristics were not significantly affected by the thickness of the thick metal layer, which creates convenience in the preparation of the structure. In general, the proposed perfect absorbers have exciting prospects in solar energy, optical sensor technology, and other related fields.

Numerical Study of Ultra-Broadband Metamaterial Perfect Absorber Based on Four-Corner Star Array

In recent years, research on solar absorbers provides a significant breakthrough to solve the energy crisis. A perfect solar absorber based on a four-corner star array is designed and the absorption performance is analyzed numerically. The results show that the absorber reaches more than 90% of the full band in the range of 400-2000 nm. In particular, the absorption efficiency of the continuous more than 95% of the bandwidth reached 1391 nm, and the average absorption efficiency of the whole study band is more than 98%, and the loss of the solar spectrum only accounted for 2.7%. At the same time, the absorption efficiency can be adjusted by changing the geometric structure of the absorber. In addition, due to the perfect symmetry of the structure, it has an excellent insensitivity of the incident angle and polarization angle. In general, the proposed solar absorber has exciting prospects in solar energy collection and utilization, photothermal conversion and other related fields.