Colloidal self-assembly based ultrathin metasurface for perfect absorption across the entire visible spectrum

Abstract Perfect absorption over the entire visible spectrum can create a dark background for acquiring images with high contrast and improved resolution, which is crucial various applications such as medical imaging, biological detection, industrial non-destructive testing. The broadband desired to be achieved in an ultrathin structure low noise well integration. Here, we experimentally demonstrate metasurface perfect absorber thickness of 148 nm large area ∼10 cm 2 . Such metasurface, more than 97% wavelength range from 400 800 nm, composed chromium nanodisk hexagonal array deposited on substrate silica spacer. A self-assembly based colloidal lithography nanofabrication method developed scalable fabrication proposed nanostructure. We attribute spectrally overlapped Fabry–Perot resonance, surface plasmon polariton, localized resonances. Our results offer novel approach wafer-scale low-cost manufacturing absorption-based devices high-contrast imaging optical modulation.