Chemical Characterization of Nanowires

Nanostructures, such as nanowires and nanorods and functionalized nanovehicles are of growing interest for various applications in nanotechnology, be that nano-electronics or drug delivery in the human body.

Multilayered III-V-nanowires to be applied in the development of single electron transistors were investigated using 0.12 sr at 22° TOA. This sample was kindly provided by Laboratorio NEST, part of Scuola Normale Superiore Pisa in Italy. Hyperspectral mapping, Bruker’s “HyperMap” which saves a spectrum for each pixel, allows careful on- and offline analysis of the acquired data. The element distribution in the nanowires can be reproduced correctly after deconvolving overlapping element lines. The deconvolution of the overlapping Au Mα and P Kα lines (see spectrum) is crucial to correctly represent the gold catalyst particle visible at the tip of the nanowire. 4x4 pixel binning was used to enhance statistics . The single P-rich layers of a thickness down to 1.5 nm are clearly distinguishable, as shown in the maps and the extracted quantified line scan. The quantified element profile of the extracted line scan also shows that the Indium concentration stays at 50 % whereas As and P are exchanging each other to form the other 50 % of the nanowire composition.