Flow-Directed Growth of Aligned Metal Nanowire Films: Toward Light-Polarizing Transparent Conductors

We present a unique technique for the aligned growth of metal nanowires (NWs) in an aqueous environment under the shear-force of laminar flow of the aqueous solution applied during NW formation on a substrate. It is based on alignment of self-assembled CTAB (cetyltrimethylammonium bromide) surfactant template nanostructures formed around seed metal particles by the shear-force. The obtained silver-based NW films exhibit anisotropic sheet resistance and linear polarization of the transmitted light in the visible range, which is opposite to the polarization characteristics of regular wire-grid polarizers due to localized plasmon resonances in the visible range and near-infrared. Nickel-based NWs, on the other hand, produced partial transmitted light polarization which was consistent with standard wire grid polarizers. The polarization results are supported by finite difference time domain simulations.