New technology for metal nanorods formation

The ongoing research on a new technology suitable for the large-scale fabrication of arrays of metallic nanorods suitable as nanoantenna dipole electromagnetic collectors is presented. The actual diameter and the height of the nanorods, centered approximately at the middle of the visible spectrum, have been settled as D ∼25nm and H ∼250nm, respectively, in order to obtain a nanodipole antenna. The experimental work was carried on in two steps: first the synthesis of a template of anodic porous alumina by a two-step anodizing process of a 1100nm thick Al film, later the growing of the metallic nanorod inside the nanopores of the anodic template. It was used a new electroless metallic deposition method, based on a redox reaction of displacement realized by immersing the samples of nanoporous alumina into an acid solution made with cupric sulfate. Detailed scanning electron microscopy analysis of the samples structure is presented. SEM images show a copper nanorod with H = 35nm and D = 300nm.