Vanadium nitride-based ultra-wideband nearly perfect metamaterial absorber

Vanadium nitride (VN)-based metamaterial absorber was investigated for ultra-wideband (UWB) nearly perfect absorber in the visible to infrared regime of the electromagnetic spectrum considering four different VN samples, namely VN6, VN8, VN10, and VN12. The absorption properties were extracted for the transverse electric and transverse magnetic incidence waves under different obliquities, and also, considering different parametric conditions of the metamaterial. The constitutive properties of VN samples were initially extracted, followed by the effective constitutive properties of metasurface comprising the nanostrips of VN6 and VN10 mediums as the illustrative examples. The results determine achieving nearly perfect UWB absorption in the stated regime of operating wavelength. Spectral characteristics were also obtained while using other reflectors at the bottom. The results demonstrate using VN at the bottom yields significantly improved spectral features. The absorption related results were also evaluated exploiting the interference theory, and the obtained discrepancies were highlighted.