Figure 3. Normalized scattering cross-sections of the NPs.

(a) The front surface located spherical Al NPs with diameters D = 120 nm and 220 nm and Ag NPs with diameters D = 100 nm and 240 nm, and (b) the hemispherical Ag NPs embedded in the SiO₂ with diameters D = 160 nm, 200 nm and 240 nm.