Abstract:
When nanorods of Au, Ag and some other elements are aligned with a preferred orientation with
respect to light, their optical extinction characteristics become dependent on the polarization and
angle of incidence of the light. This effect is explored here and it is shown that it could potentially
be exploited to produce a ‘colour-change coating’. However, particle–particle interactions are also
likely to occur in such coatings, with red shifting of extinction spectra occurring for end-on-end
configurations of monodisperse rods, and blue shifting for side-by-side configurations.
Surprisingly, the particle–particle interactions are attenuated if they are between rods of differing
aspect ratios, and this offers a useful new means of control of the optical properties of coatings of
nanorods.
