Fig. 5.
Large-scale assembly of particles into linear and circular templates. (A) SEM image of an array of octahedra trimers in identical-sized pits in Si. Measuring these arrangements side-by-side enables interrogation of SERS enhancement of each trimer under identical excitation conditions. (B) SSEFs at λex = 633 and 785 nm for single particles, dimers, trimers, and tetramers composed of nanocubes (a = 122 nm), octahedra (a = 300 nm), and mildly etched octahedra (a = 270 nm). Light was polarized along the long axis of the particle assembly. Error bars correspond to the SD of each measurement. (C) SEM images of octahedra packed into circular pits of varying diameter with a depth of 300 nm (1–5) and 650 nm (6–10). (D) SERS EFs measured at 785 nm excitation for individual circular single-layer and multilayer octahedral assemblies (1–10).