Templated assembly of metal nanoparticles in nanoimprinted patterns for metal nanowire fabrication

We have developed a new method that combines nanoimprint lithography and metal nanoparticle solution processing for fabricating metal nanowires. A polymer template with nanoscale features, fabricated by nanoimprint lithography, provided physical reservoirs which were filled with a silver nanoparticle solution during the spin-coating. After the lift-off process, the defined silver nanoparticle patterns were annealed to enhance the conductivity for use as electrodes. Silver nanowire patterns (500 nm linewidth with a 300 nm gap) were fabricated without using an expensive high-vacuum system for metal deposition. This method demonstrated pattern resolution enhancement compared with ink-jet printing which inherently suffers from ink spreading on the substrate surface. By using this method, organic thin film transistors composed of the solution-processed silver source/drain electrodes with a channel length of 300 nm were fabricated and showed comparable behaviors to those with vacuum-deposited electrodes.