The strong light scattering from SPR has received an extraordinary attention due to the useful applications in photodetectors and cell and biomedical imaging. However, the applications using light scattering require a high scattering cross-section along with low absorption losses near the resonance wavelength. In this paper, effective plasmonic scattering of three-layered Au–Ag bimetallic nanoshells with a dielectric separate layer has been studied using the quasi-static approximation of classical electrodynamics. Because of the surface plasmon resonance (SPR)-induced intense light absorption, the effective scattering intensity is much weaker than that of scattering cross-section. However, the effective scattering intensity could be improved by tuning the geometric dimension and local dielectric environment of the nanostructure. It has been found that the greatest effective scattering takes place when the outer Ag nanoshell has a thick thickness or the dielectric separate layer has a small dielectric constant. The effective scattering also depends on the inner Au sphere radius and outer surrounding dielectric constant. Because of the mode transformation of the SPR, the effective scattering could also be greatly improved when the inner Au sphere has a very small or large size. However, the effective scattering intensity changes non-monotonously as the surrounding dielectric constant increases. The greatest effective scattering could be obtained when the surrounding dielectric constant has an intermediate value. This tunable effective plasmonic scattering of Au@Ag three-layered nanoshells presents a potential for design and fabrication of plasmonic optical nanodevice based on resonance light scattering.

由于在光电探测器以及细胞和生物医学成像中的有用应用，来自 SPR 的强光散射受到了极大的关注。然而，使用光散射的应用需要高散射截面以及共振波长附近的低吸收损耗。在本文中，使用经典电动力学的准静态近似研究了具有介电分离层的三层 Au-Ag 双金属纳米壳的有效等离子体散射。由于表面等离子体共振 (SPR) 诱导的强光吸收，有效散射强度比散射截面弱得多。然而，可以通过调整纳米结构的几何尺寸和局部介电环境来提高有效散射强度。已经发现，当外银纳米壳具有较厚的厚度或介电分离层具有较小的介电常数时，会发生最大的有效散射。有效散射还取决于内部 Au 球半径和外部周围介电常数。由于 SPR 的模式转换，当内部 Au 球的尺寸非常小或非常大时，也可以大大提高有效散射。然而，随着周围介电常数的增加，有效散射强度非单调变化。当周围的介电常数具有中间值时，可以获得最大的有效散射。