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Description
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The control over crystalline defects is of extreme importance when growing functional materials, since their presence may alter the final behavior (opto‐electronic properties) and evolution of the growing system (orientation and shape). In the present work we address both phenomena in the particular case of InSb related nanostructures. On one hand, heterostructured architectures may show interfacial dislocations if reaching the coherency limit, which is dependent on geometrical constrictions of the systems in addition to the mismatch between phases. In this context, it is usually assumed that the mismatch strain in axial heterostructured nanowires is mainly relaxed by elastic distortion of the lattice, although theoretical calculations predict the formation of misfit dislocations[1]. It is remarkably important unveiling whether the partial/total lattice relaxation takes place through elastic and/or plastic mechanisms since both will affect the material performance. Interestingly, the location and shape of the heterointerfaces, as well as possible diffusion phenomena involved, may hinder the understanding of the actual relaxation mechanism, as we show in the case of axial InAs/InSb nanowires[2]. Contrary to most reported works, we find out the presence of misfit dislocations at the core of the system while there is a huge plane bending through the edges of the nanowires. On the other hand, we correlate the systematic observation of a lateral twin boundary with the morphological transition from nanowires to membrane‐like systems, called nanosails. Based on the experimental data gathered, consisting on SEM and aberration‐corrected STEM measurements, including polarity determination[3], we are able to establish the underlying defect‐driving growth mechanism leading to the formation of membrane‐like structures growing aside InAs/InSb nanowires[4], showing excellent transport properties. Possible instabilities during the growth may promote the sinking of the catalytic droplet to wet one sidewall, leading to the nucleation of the lateral twin that opens the way for the broadening of the system. (2016-12-20)
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Keyword
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Nanowire, Materials science, Context (archaeology), Condensed matter physics, Lattice (music), Relaxation (psychology), Dislocation, Bending, Nanotechnology, Physics, Composite material |
