Effect of Substrates on Femtosecond Laser Pulse-Induced Reductive Sintering of Cobalt Oxide Nanoparticles.

Direct writing of cobalt/cobalt oxide composites has attracted attention for its potential use in catalysts and detectors in microsensors. In this study, cobalt-based composite patterns were selectively formed on glass, polyethylene naphthalate (PEN), and polyethylene terephthalate (PET) substrates via the femtosecond laser reductive sintering of CoO nanoparticles in an ambient atmosphere. A CoO nanoparticle ink, including the nanoparticles, ethylene glycol as a reductant, and polyvinylpyrrolidone as a dispersant, was spin-coated onto the substrates.