Plasmonic nanocrystals (PNCs) have received much attention due their variety of applications, including in medicine, energy, chemical sensing, optics, and security. The diversity of these applications arises from the sensitivity of the localized surface plasmon resonance (LSPR) to the PNC’s size, shape, composition, and environment. There are many PNCs available for use, but one of the most promising types are branched PNCs, where electric field enhancement at their tips is possible. In this study, seed-mediated co-reduction was employed to illuminate the influence of planar defects during branch growth processes. Au nanocrystals (decahedra, icosahedra, pentatwinned rods, and triangular nanoprisms) rich with twin planes and stacking faults were selected as seeds to understand the correlation between branch growth and planar defects. Interestingly, the observations of PNC stellation, which is a specific extension of the edges and face to form a new “vertex”, indicates that planar defects redirect the growth of branches from the high-energy vertices to the more labile faces. This result can be attributed to the distribution of surface strain in the initial Au seeds. Finite-difference time-domain (FDTD) simulations were used to investigate the near and far electric field behaviors of the stellated PNCs. The findings of this work provide new rules for branch growth from Au seeds with planar defects, and these rules can be applied as general guidelines for other planar defect rich systems.

Role of planar defects during the synthesis of stellated plasmonic nanocrystals

255th National Meeting (2018)

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