Study on Extinction Properties of Nanoparticles with Hybrid Core-Shell Structure

Based on the discrete dipole approximation (DDA) method, we studied the effects of different materials and thicknesses on extinction properties of the nanoparticles with a hybrid core-shell structure. The different core-shell structures can be used as sensors or to enhance sensitivity of sensors. For those uses, this article describes the application of DDA simulations to establish the extinction properties of hybrid nanoparticles fabricated with different materials associated with the different core-shell structures. The extinction efficiencies of core-shell structures were stronger than those of hybrid nanoparticles with other combinations of structures or of the single metal nanoparticles. As the shell's thickness was increased, the absorption properties in extinction spectra of different hybrid nanoparticles were changed from that of elemental core metals to that of shell metals, and the absorption peaks of extinction spectra widened. In addition, the DDA method was used to analyze absorption properties in extinction spectra of core-shell nanoparticles with different materials (silver, gold, silicon, and silicon dioxide). We found that the properties of the shell materials were the key factors in influencing the extinction properties of the hybrid nanoparticles with core-shell structures.