Rapid formation of nanostructures in Au films using a CO₂ laser

Abstract

We systematically investigate the formation of nanostructures in magnetron-sputtered Au films using a CO₂ laser. By comparing the optical properties and surface morphologies of Au films on different kinds of substrates before and after laser irradiation with different laser powers and irradiation times, we find that the nanostructures are most rapidly formed in the Au film with 5 nm thickness on a thin glass substrate. With the laser power of 6 W and a beam diameter of ∼10 mm at the Au film, only a few tens of seconds of irradiation time is sufficient to induce nanostructures with the area size of ∼10 mm in the 5 nm Au film on a thin glass substrate.