$Cu_{2-x}S$ induced plasmonic modulation for mechanically robust flexible copper electrodes

Abstract

With the advent of modern electronics, metal nano-particles have been used for several applications such as transparent electrodes, solar cells, sensors and other electronic devices. Among the various metals, Copper deserves special recognition because of the high electrical conductivity and cost effectiveness. However, Copper suffers from the drawback of rapid oxidation when exposed to ambient conditions. Copper chalcogenides, $Cu_{2-x}S$, have varying stoichiometric coefficients ranging from x= 1 to 2. The vacancies present in the chalcogenides imply that these nanoparticles have appreciable free carrier density. The free carrier density can be tuned by doping, temperature and phase transition. These vacancies have been recently shown to exhibit plasmonic absorption in NIR region, which in turn, leads to localized heating and enhanced electric field when irradiated by flash. The localized heating, on flash irradiation of deposited ink patterns, can lead to intensive plasmonic welding and formation of robust electrodes.