Transparent Metal-Mesh heater using Silver-coated copper nanoparticles sintered with intense pulsed light irradiation on PET substrate

A transparent metal-mesh heater was fabricated by intense pulsed light (IPL) sintering of copper-based particle ink on a polyethylene terephthalate (PET) substrate having a low glass transition temperature. The metal-mesh electrode with a line width of 9 µm was formed by filling imprinted intaglio patterns with silver-coated copper particle ink. This silver-coated copper particle is based on inexpensive copper and has excellent oxidation resistance as pure silver particle at temperatures up to 150 °C, making it suitable as a metal particle for metal-mesh heaters. This metal ink was IPL-sintered for the short time of 20 ms to obtain a transparent electrode with a low sheet resistance of 2Ω/sq. without deterioration of the PET substrate. The silver thin film coated on the surface of the copper particles not only effectively blocks the reduction heat that may occur during the IPL sintering process, but also plays an important role in preventing the oxidation of copper during the operation of the transparent heater. It was confirmed that this flexible heater with 85% transparency is capable of stable operation up to 130 °C at a low voltage of 9 V.