Gold Nanowire Bundles Grown Radially Outward from Silicon Micropillars

One-dimensional (1D) micro- and nanostructures have become increasingly popular because of their tremendous prospect in various applications. While the design and fabrication of these structures from a single component in two-dimensional (2D) arrays is common, the attainment of hierarchical three-dimensional (3D) architectures made up of multicomponent one-dimensional structures is rare. Herein we report, for the first time, the lateral growth of gold nanowires from the sidewalls of substrate grown silicon micropillars to form a unique "wire-on-pillar" architecture. Unlike zero-dimensional (0D) point-like, 1D linear, and 2D planar Au structures, the obtained 3D "wire-on-pillar" Au architecture provides abundant hotspots between adjacent Au wires, which led to remarkably high surface-enhanced Raman scattering (SERS) signals.