Using Mie-theory and literature values for the refractive indices of doped ZnO, we calculated the extinction cross-section of core@shell particles with 40 nm diameter cores and 15 nm thickness shells with Al 3+ dopant percentages of 0, 2 and 5 at.% (Figure ). The position of the LSPR shifts towards shorter wavelengths for particles with increased dopant concentration, qualitatively reproducing the trend observed in our experimental spectra (Figure ). and simulated data vs. aluminum dopant percentage. The measured spectra for the 0, 1, and 2 at.% doping correspond to Au@AZO NPs with dimensions of 121 ± 8 nm (0 at.% Al), 130 ± 9 nm (1 at.% Al), and 127 ± 6 nm (2 at.% Al), as obtained from an analysis of the SEM images in Figure .