Gold/boron core-shell nanocables synthesized from gold-boron eutectic droplets.

Metal/semiconductor core-shell coaxial nanocables are promising building blocks for nanoelectronic devices while in situ growth of these nanocables remains challenging due to the distinctly different synthesis temperature ranges required for metals and semiconductors. To overcome this difficulty, we have developed a vapor-liquid-solid and oxide-assisted bimodal competition growth strategy for in situ metal/semiconductor core-shell nanocable growth. Using this process, gold/boron core-shell nanocables were obtained. A core-shell Au-B/BO(x) eutectic droplet formed via hydrogen gas-assisted rapid cooling was found critical for initiation of the nanocable growth. In addition, the large difference in the boron nanowire growth rates in the vapor-liquid-solid and oxide-assisted mechanisms facilitates the layered growth in the nanocables. The compatibility of this method with the vapor-liquid-solid process applied widely for semiconductor nanowire growth allows in situ connection of metal/semiconductor nanocables with semiconductor nanowires.