Self-assembled shape- and orientation-Controlled synthesis of nanoscale Cu₃Si triangles, squares, and wires

Controlling shape and orientation is important for the synthesis of functional nanomaterials. In this work, nanoscale Cu₃Si triangles, squares, and wires have been grown on Si(111), (100), and (110) substrates, respectively, through a template-free Au-nanoparticle-assisted vapor transport method. The sides of nanotriangles and nanosquares and the growth direction of the nanowires are all along Si 〈110〉, giving rise to long- range ordering of the nanostructures. Au nanoparticles absorb Cu vapor and facilitate the rate-limited diffusion of Si, which is critical for the shape-controlled growth of Cu₃Si. This bottom-up approach to synthesize shape- and orientation-controlled Cu₃Si nanostructures might be applicable to the tailored growth of other materials.