Optical evaluation of nanocomposite metamaterials fabricated by nano-printing technique utilizing silver nanoink

摘要

We develop a new approach to fabricate three-dimensional (3D) nanocomposite metamaterials formed with the use of a nano-printing technique based on silver nanoink, and we experimentally investigate their optical performance. Nanocomposite metamaterials are formed in the grooves of nanodisks and split-ring resonator (SRR) shapes, and the optical properties of the specimens are evaluated and compared based on the metamaterial sintering conditions. For the nanocomposite nanodisk, two notable resonances are observed in the visible spectral region. In particular, at a wavelength of 430 nm, the absorbance reaches 99.5%, which is greater than the calculated result for bulk silver nanodisk arrays. Via modification of the nanodisk structures, nanocomposite nanodisks based on nanoink can be applied as perfect broadband absorbers. For the nanocomposite SRR, we confirm that there is a unique optical resonance in the SRR before sintering, and the Q-factor is estimated to be 9.1, which is higher than that of the SRR after sintering. In addition, we experimentally demonstrate that the optical properties of the nanocomposite metamaterials can be modulated depending on the choice of nanoink material. Since optical anisotropy is also observed in the nanocomposite SRR, we conclude that the obtained optical spectra are influenced by the shape of the structures.