Theoretical study of the effect of geometrical parameters on the effective scattering of gold-dielectric-silver three-layered nanoshells

The strong light scattering generated by localized surface plasmon resonance has attracted great interest due to its usefulness in SERS, biological tissues, cells, and sensors. The application regions of light scattering require a higher scattering and a lower absorption loss near the plasmon resonant wavelength. The geometric parameters of nanoshells have a significant effect on scattering. In order to fully understand how to improve the effective scattering, the effects of the surrounding dielectric constant, the middle dielectric constant, and its geometric parameters on the effective scattering of gold-dielectric-silver three-layered nanoshell are studied in detail based on quasi-static theory. The results show that effective scattering can be improved by increasing the surrounding dielectric constant and reducing the middle layer dielectric constant. Because of the mode transformation, it has also been found that the effective scattering could be improved with a smaller inner gold sphere radius, a suitable middle dielectric layer radius, and an outer silver nanoshell radius. The tunable effective scattering of gold-dielectric-silver three-layered nanoshell provides a method for analyzing optical properties and also broadens their applications in nanophotonic devices.