Nanoscale electron tomography and compositional analysis of Aerotaxy nanowires

Sammanfattning: One common goal of sample analysis is to provide structural, compositional, or functional data in order to improve production parameters. One instrument specialized in such structural and compositional analysis with a high spatial resolution is the transmission electron microscope (TEM). The high-end microscopes have the capability of sub-Ångström resolution and compositional quantification and distribution, which makes it the instrument of choice for many different research fields. For example, the composition, crystallography, and overall morphology of semiconductor nanowires is highly dependent of the multi-parameters space of the growth, and needs the high resolution analysis and imaging. Here we present the use of TEM for structural, compositional and morphological analysis of semiconducting nanowires grown by Aerotaxy, which is a technique for growing nanowires without the need for an expensive single crystalline substrate. This, in combination with it being continuous holds high hopes for industrial application of nanowires in the future. The TEM analysis provides high resolution micrographs of the single crystalline nanowires for growth quality evaluation, as well as compositional analysis, whereas electron tomography (ET) is used to determine the general morphology of the nanowires by reconstructing 3D images of the wires. The 3D data is especially used for surface features, and provides data for topological surface maps of the wire, which we have named azimuthal maps. Hopefully the data can provide more insight in the growth mechanism of Aerotaxy making highly controlled growth possible.