The preparation of conductive and transparent gold/silver nanowire mesh films is reported. The nanowires formed after the reduction of the metal ions was triggered and a thin growth solution film was spread on a substrate. Metal reduction progressed within a template of a highly concentrated surfactant liquid crystalline mesostructure formed on the substrate during film drying to form ordered bundles of ultrathin nanowires. The films exhibited metallic conductivity over large areas, high transparency, and flexibility.

We report on in situ, self-assembly, solution-processing of metallic (Au/Ag) nanowire-based transparent electrodes integrated to vertical organic field-effect transistors (VOFETs). In the VOFET architecture, the nanowires' microstructure facilitates current modulation by the gate across the otherwise shielding sandwiched source electrode. We show N-type VOFETs operation with on/off ratio ∼1 × 10(5) and high current density (>1 mA cm(-2) at VDS = 5 V). The integration of the device design and the transparent electrode deposition methods offers a potential route for all-solution processing-based, large-area, high-efficiency organic electronics.

Gold/silver nanowires (NWs) of controlled diameters were synthesized from catalytic metal seed particles at the substrate/solution interface. Small seed nanoparticles of three different sizes: ~1 nm (11 gold atoms), ~1.4 nm (~55 gold atoms), and homemade nanoparticles of ~2 nm were used. By varying a single type of seed particle concentration in the growth solution, the NW diameters and morphology could be controlled, between bundles of ultrathin NWs of ~2-3 nm diameter to thicker isolated single NWs with a mean diameter of ~16 nm. In addition, the catalytic reduction rate leading to NW growth was found to be seed size dependent at small seed sizes (<2 nm). The two types of metallic NW films were tested for their performance as transparent electrodes after additional metal deposition for their stabilization and conductivity enhancement. The thin NW bundles exhibit superior transparent conductor properties.

A simple wet chemical approach was developed for a unique on-surface synthesis of transparent conductive films consisting of ultrathin gold/silver nanowires directly grown on top of CdSe nanowire array photoconductive devices enclosed in polycarbonate membranes. The metal nanowire film formed an ohmic contact to the semiconductor nanowires without additional treatment. The sheet resistance and transparency of the metal nanowire arrays could be controlled by the number of metal nanowire layers deposited, ranging from ∼98-99% transmission through the visible range and several kOhm/sq sheet resistance for a single layer, to 80-85% transmission and ∼100 Ohm/sq sheet resistance for 4 layers.