Ultra-broadband and tunable infrared absorber based on VO₂ hybrid multi-layer nanostructure

Abstract

We propose an ultra-broadband near- to mid-infrared (NMIR) tunable absorber based on VO2 hybrid multi-layer nanostructure by hybrid integration of the upper and the lower parts. The upper part is composed of VO2 nano cylindrical arrays prepared on the front illuminated surface of quartz substrate, and VO2 square films and VO2/SiO2/VO2 square nanopillar arrays prepared on the back surface. The lower part is an array of SiO2/Ti/VO2 nanopillars on Ti substrate. The effects of different structural parameters and temperature on the absorption spectra were analyzed by the finite-difference time-domain method. An average absorption rate of up to 94.7% and an ultra-wide bandwidth of 6.5 μm were achieved in NMIR 1.5-8 μm. Neither vertical incident light with different polarization angles nor large inclination incident light has a significant effect on the absorption performance of the absorber. The ultra-broadband high absorption performance of this absorber will be widely used in NMIR photodetectors and other new optoelectronic devices.

Study of the photothermal response of a multilayer structure doped with VO2@Au nanoshells

“…Finally, we perform numerical calculations to determine the electric field distribution within the MLS for wavelengths of 658 nm and 747 nm, considering specific values of incident CW laser intensities both before and after the phase change in the VO 2 core. There are many comprehensive studies on phase change materials within a MLS with the use of numerical methods; this paper presents a step-by-step analytical solution to the coupled equations [23][24][25]. The derived solutions offer valuable insights, particularly for individuals new to the field.…”