Wavelength Dependence of Laser-Induced Nanowelding on Silver Nanopartcles*

Nanowelding of metallic nanoparticles induced by laser illumination is of particular interest because it provides convenient and controlled means for shape-conversion of nanoparticles and fabrication of nanodevices. Previously, we exploited fluorescence microscopy to directly image the real-time nanowelding kinetics of silver nanoparticles (AgNPs) when illuminated with a continuous wave blue laser and investigated the kinetics of the laser-induced nanoparticle nanowelding. In the currenty study, we measured the dependence of the shape of the nanowelded microstructures of AgNPs on the wavelengths of laser illumination. The measured wavelength-dependence was then understood by examining the surface electric field enhancement due to surface plasmon resonance. This work is expected to facilitate the development of better nanowelding strategies of metallic nanoparticles for broader applications.