High efficiency broadband near-infrared absorbers based on tunable SiO2-VO2-MoS2 multilayer metamaterials

Abstract

This paper proposes a novel model for an high-efficiency tunable broadband near-infrared absorber. The proposed absorber consists of an Al bottom mirror, SiO2-VO2 hybrid spacing layer, and certain MoS2 top nanostructures. Owing to the thermal tunability of the refractive index of VO2 materials, the near field coupling resonance in the multilayer metamaterials can be tuned by regulating the temperature, and henceforth, the efficiency of the absorber and the absorption band are also tunable. MoS2 has an excellent thermal-stability in the near-infrared range, which can nullify the influence of the temperature regulation of VO2. The results from our study demonstrated that the absorber achieved an average absorbance of 86.5% at 75 °C for a broadband range of 800–2350 nm. At 25 °C, the absorber attained an average absorbance of 96.6% for the wavelength range of 800–1160 nm, and a narrow-band absorption peak around 1489 nm. The absorber we have studied, which was based on tunable metasurfaces, displays tremendous potential for the applications such as camouflage coatings, solar energy, information sensing, and atmospheric environment monitoring.

Keywords

• Multilayer metamaterials
• Near-infrared
• Absorbers
• Thermal tunability