Direct laser planting of hybrid Au-Ag/C nanostructures - nanoparticles, flakes and flowers

Abstract

We demonstrate a new approach for forming hybrid metal/carbonaceous nanostructures in a controlled direct laser planting process. Au-Ag nanoclusters in amorphous or crystalline carbonaceous matrices are formed with different morphology: nanoparticles, nanoflakes, and nanoflowers. In contrast to other generation techniques our approach is simple, involving only a single laser-induced process transforming supramolecular complexes dissolved in solvent such as acetone, acetophenone, or dichloroethane into hybrid nanostructures in the laser-affected area of the substrate. The morphology of the hybrid nanostructures can be steered by controlling the deposition parameters, the composition of the liquid phase and the type of substrate, amorphous or crystalline. The carbonaceous phase of the hybrid nanostructures consists of hydrogenated amorphous carbon in the case of nanoparticles and of crystalline orthorhombic graphite of nanoscale thickness in the case of flakes and flowers. To the best of our knowledge this is the first demonstration of the fabrication of orthorhombic graphite with metal nano inclusions. The remarkable quality and regularity of the micron-sized nanoscale thickness single crystal flakes allows for cutting high resolution nano scale structures, which in combination with the metallic nano inclusions offer much design freedom for creating novel devices for nano photonic applications. The encouraging properties of the nanomaterials with different composition, size and shape stimulate the development of efficient synthesis strategies aimed at fine-tuning the functionality.