Nanosized-laser-induced sub-20nm homogenous alloy nanoparticles.

Alloy nanoparticles (NPs) have great potential in nanosized 3D-printing, surface coating, plasmonic enhancement, information coding, and so forth. However, chemical-pollution-free and homogeneous sub-20nm NPs maintain still a challenge in preparation. Here we present a smart nanosecond laser scan strategy of alloy-NPs preparation on a bilayer metal film by using a nanosized focused beam, sucessfully realizing controllable fabrication of the sub-20nm homogeneous alloy NPs without pollution. As demonstration, various sub-20nm AgCu GPs with different volume ratios have been prepared, all GPs show narrow size distribution and uniform interparticle spacing. The simple and cost-effective method is a stable and adaptable for other alloy-GPs such as AuAg GPs. In addition, such alloy NPs exhibit two-peak plasma resonance feature and information cording capacity. We believe that homogenous alloy sub-20nm GPs will provide new application opportunities in many fields.&#xD.