Controllable femtosecond laser-induced dewetting for plasmonic applications

Dewetting of thin metal films is one of the most widespread method for functional plasmonic nanostructures fabrication. However, simple thermal‐induced dewetting does not allow to control degree of nanostructures order without additional lithographic process steps. Here we propose a novel method for lithography‐free and large‐scale fabrication of plasmonic nanostructures via controllable femtosecond laser‐induced dewetting. The method is based on femtosecond laser surface pattering of a thin film followed by a nanoscale hydrodynamical instability, which is found to be very controllable under specific irradiation conditions. We achieve control over degree of nanostructures order by changing laser irradiation parametrs and film thickness. This allowed us to exploit the method for the broad range of applications: resonant light absorbtion and scattering, sensing, and potential improving of thin‐film solar cells. A novel method for single‐step, lithography‐free, and large‐scale laser writing of nanoparticle‐based plasmonic structures has been developed. This method has an advantage over the most previously demonstrated methods in its simplicity and versatility, while the quality of the structures is good enough for many applications. In particular, resonant light absorbtion/scattering and surface‐enhanced Raman scattering have been demonstrated on the fabricated nanostructures.