Fabrications of Nanocomposite Gold-Polymer Metamaterials Consisting of Periodic Microcavities with Tunable Optical Properties

Abstract Nanocomposite gold-polymer metamaterials (MMs) were developed in a series of steps. The colloidal gold nanoparticles (Au NPs) were prepared using seeding growth technique. The NPs were then electro-deposited into the micro-pattern structure of polymer thin film formed on the surface of indium tin oxide substrates (ITO). This micro-pattern structure made of positive photoresist (PR) polymer were present in the well-ordered square microcavities in the size range of 52–65 μm (length), 1.3–1.6 μm (depth) and 17–29 μm (interspace length). Field emission scanning electron microscopy (FESEM), scanning transmission electron microscopy (STEM) and atomic-force microscopy (AFM) images confirmed the presence of Au NPs within the microcavities. This nanocomposite was named as patterned Au-PR/ITO and was compared with random-patterned Au-PR/ITO and the bare PR/ITO. The change of refractive index and complex permittivity in the UV–vis range revealed that the periodic arrangements of microcavities containing the Au NPs could result in new exploration in the optical and electromagnetic properties.