Strawberry Silver/SiO2 Structure: Synthesis and Its Optical Resonances

Metal nanoshells, consisting of a dielectric core with a metallic shell of nanometer thickness, are a new, composite nanoparticle whose optical resonance can be designed in a controlled manner. By varying the ratio of the silver ammonia solution to the silicon dioxide solution, we fabricated a strawberry silver/silicon dioxide structure, whose optical resonance is very similar to the nanoshell structure. Their optical resonance frequency can be varied over tens of nanometers in wavenumbers. We discuss their resonance quantity with the nanoshell resonance theory. The microstructures of the silver nanoparticle-coated silver/silicon dioxide microspheres were characterized by transmission electron microscopy (TEM).