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peer-reviewed Herein, we report a novel approach to form axial heterostructure nanowires composed of linearly distinct Ni silicide (Ni2Si) and Si segments via a one-pot solution synthesis method. Initially, Si nanowires are grown using Au seeds deposited on a Ni substrate with the Si delivery in the solution phase using a liquid phenylsilane precursor. Ni silicide then forms axially along the wires through progressive Ni diffusion from the growth substrate, with a distinct transition between the silicide and pure Si segments. The interfacial abruptness and chemical composition of the heterostructure nanowires was analysed through transmission electron microscopy, electron diffraction, energy dispersive X-ray spectroscopy, aberration corrected scanning transmission electron microscopy and atomically resolved electron energy loss spectroscopy. The method represents a versatile approach for the formation of complex axial NW heterostructures and could be extended to other metal silicide or analogous metal germanide systems.

peer-reviewed Here we describe a relatively facile synthetic protocol for the formation of Si-Ge and Si-Ge-Si1-xGex axial nanowire heterostructures. The wires are grown directly on substrates with an evaporated catalytic layer placed in the vapour zone of a high boiling point solvent with the silicon and germanium precursors injected as liquids sequentially. We show that these heterostructures can be formed using either indium or tin as the catalyst seeds which form in situ during the thermal anneal. There is a direct correlation between growth time and segment length allowing good control over the wire composition. The formation of axial heterostructures of Si-Ge-Si1-xGex nanowires using a triple injection is further discussed with the alloyed Si1-xGex third component formed due to residual Ge precursor and its greater reactivity in comparison to silicon. It was found that the degree of tapering at each hetero-interface varied with both the catalyst type and composition of the NW. The report shows the versatility of the solvent vapour growth system for the formation of complex Si-Ge NW heterostructures. ACCEPTED peer-reviewed