The realization and synthetic control of complex core/shell nanowires have led to the development of promising materials for various applications. Here, we report a new synthesis of core/shell nanowire structures that exploits the Plateau-Rayleigh instability of 1-dimensional materials. Using this approach, which we term Plateau-Rayleigh crystal growth, we deposit Si (Ge) onto uniform-diameter Si (Ge) nanowire cores to generate diameter-modulated structures. The periodicity, diameter-modulation amplitude and cross-sectional morphology of the nanowires were broadly tunable through rational control of reaction conditions during shell growth. For example, synthesis on a large nanowire core yielded a structure with maximum/minimum shell diameters of 400/250 nm and a periodicity of 2 �m. In addition, shell synthesis on smaller nanowire cores showed that the modulation amplitude can be greatly enhanced with maximum/minimum diameters of 250/30 nm and 500 nm pitch. Analysis of the results reveals that reductions in surface energy drive the formation of diameter-modulated structures, and that kinetic control of reaction rates enables the synthetic tunability. We suggest that Plateau-Rayleigh crystal growth, which is unique to 1-dimensional structures, represents a general paradigm for synthesizing diameter-modulated nanowires with complex morphologies for many different materials and material combinations.

Plateau-Rayleigh crystal growth of periodic shells on nanowires

248th National Meeting (2014)

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