Influence of Ag nanoparticles on femtosecond laser-induced Cu precipitation from glyoxylic acid copper complex ink

This study investigates the role of Ag nanoparticles (NPs) in glyoxylic acid copper (GACu) complex inks in influencing Cu precipitation under femtosecond laser pulse irradiation. The nonlinear optical absorption properties were evaluated using the open-aperture z-scan method, revealing that Ag NPs significantly enhance absorption by acting as nucleation sites for Cu NP formation. Pump-probe measurements further confirmed that the presence of Ag NPs increases the concentration of precipitated Cu NPs and facilitates the generation of finer Cu patterns. Scanning electron microscopy of the fabricated patterns demonstrated that GACu complex ink supplemented with Ag NPs achieved a minimum line width of 5.0 µm, compared to 6.7 µm for the ink without Ag NPs. These results, which were consistent with the findings of transient phenomena evaluated using a pump-probe method, validate the capability of Ag NPs to enhance absorption and improve patterning precision at reduced energy levels, offering a viable strategy for facilitating high-purity Cu structures with enhanced patterning control.