Fabrication of nanostructure and deposition of metal particles by femtosecond laser ablation in electrolyte

Abstract

Fine structures alter surface characteristics such as tribology, light reflection characteristics, wettability and biocompatibility on the surface of materials, and LIPSS (Laser-induced periodic surface structure) fabricated by an ultrashort-pulsed laser has attracted attention for the creation of fine structures. It is able to fabricate fine periodic structures of nanoscale in a self-organizing manner by irradiating the material surface with a femtosecond laser or a picosecond laser. However, it is difficult to modify the surface in addition to creating a nanostructure since laser irradiation is generally performed in the atmosphere with low energy near the processing threshold. On the other hand, as a plating method that deposits metal locally and efficiently, it has been reported that the laser with the long pulse duration for heat processing enables surface modification by irradiating the substrate surface in electrolytes for plating. Therefore, ultrashort-pulsed laser ablation in the electrolyte has been proposed to improve processing efficiency, to clarify the phenomenon of metal deposition by laser ablation in metal solutions and to create a higher value-added surface by realizing control of the surface composition in addition to the fabrication of a nanostructure. In this study, both the fabrication of a nanostructure and the deposition of copper particles were investigated by femtosecond laser irradiation on the substrate surface in a copper sulfate solution. Femtosecond laser ablation in electrolyte fabricated a nanostructure and precipitated metal particles. Moreover, the effects of fluence and pulses on the deposition of metal particles were stated. This study demonstrated the efficacy of femtosecond laser in the electrolyte to fabricate nanostructure and to deposit metal particles on the irradiated surface.