Internal structure and quantum efficiency of hybrid metal-dielectric nanoparticles fabricated by femtosecond laser exposure of bi-layer film

We demonstrate the creation of hybrid metal-dielectric nanostructures (NPs) using femtosecond-laser exposure of copper-silicon and gold-silicon films. The formation of arrays of nanoparticles takes place in the process of irradiation of a bilayer film along a circular trajectory. The internal structure of the obtained NPs was studied by means of transmission scanning electron microscopy and energy-dispersive X-ray spectroscopy. The resulting hybrid structures represent a mixture of gold and silicon, and both considered systems demonstrate broadband photoluminescence in the range of 450 - 900 nm with a quantum efficiency of up to 1.1%.