Laser annealing of gold nanoparticles thin film using photothermal effect

The low temperature annealing process of gold nanoparticles (AuNPs) thin film was developed in this research. Photothermal effect of metal nanoparticles was used to locally anneal AuNPs thin film rather than thermal annealing, since that could absorb specific wavelength of light and then convert light energy into heat. Owing to surface plasmon resonance (SPR), AuNPs have a strong optical absorption at 520 nm. A continuous Ar laser (wavelength: 514 nm) was irradiated locally to AuNPs thin film. After laser annealing, the resistivity of AuNPs thin film is as low as that of thermal annealing AuNPs thin film (1.68 × 10 −7 Ω m) and the resistivity of AuNPs thin film would decrease with laser power. Then, the laser annealing of AuNPs thin film provides a method to realize the metallization in large-area, flexible electronics on polymer substrates.