Femtosecond laser-induced localized electrodeposition of two dimensional metal patterns

Microscale metal patterns find extensive applications in solar cells, flexible electrodes, and metal gratings. Traditional techniques for manufacturing metal patterns generally require masks, and they are also timeconsuming and inefficient. In the present experiment, an innovative femtosecond (fs) laser-induced local electrodeposition (FsLI-LECD) method was proposed. The introduction of the fs laser significantly enhanced the current density within the target region, enabling the efficient and maskless fabrication of copper (Cu) patterns. The impact of the fs laser on cathode current density was analyzed through theoretical and numerical calculations. The accuracy of the theoretical and numerical results was validated by examining the current curves at different laser single pulse energies. The composition, morphology, deposition rate, and dimensional accuracy of the coating were evaluated at different laser single pulse energies. It was found that the fs laser irradiation increased the cathode current density. The fs laser had a small thermal influence zone; thus, structural deposition at the microscale was realized. At a single pulse energy of 8 mu J, the coverage of the deposited structure at the fs laser-induced track was higher and the cathode current increased by 28 % compared with that without fs laser irradiation. Moreover, the volume deposition rate achieved an impressive value of 6.61 x 103 mu m3/s, enabling the high-efficiency fabrication of complex patterns. The Cu patterns have a hardness of 1.42 GPa, which is close to that of bulk copper. This proposed innovative approach presents a novel fabrication solution for large-area, multi-metal patterns.