Measuring Three-Dimensional Strain and Structural Defects in a Single InGaAs Nanowire Using Coherent X-ray Multiangle Bragg Projection Ptychography

• DOI: 10.1021/acs.nanolett.7b04024
• Publication Date: 2018-01-18T21:23:07Z
• Authors: Megan O. Hill; Irene Calvo-Almazan; Marc Allain; Martin V. Holt; Andrew Ulvestad; Julian Treu; Gregor Koblmüller; Chunyi Huang; Xiaojing Huang; Hanfei Yan; Evgeny Nazaretski; Yong S. Chu; G. Brian Stephenson; Virginie Chamard; Lincoln J. Lauhon; Stephan O. Hruszk...
• Keywords: Ptychography; Wurtzite crystal structure; Microscale chemistry

III-As nanowires are candidates for near-infrared light emitters and detectors that can be directly integrated onto silicon. However, nanoscale to microscale variations in structure, composition, strain within a given nanowire, as well between nanowires, pose challenges correlating microstructure with device performance. In this work, we utilize coherent nanofocused X-rays characterize stacking defects single InGaAs nanowire supported on Si. By reconstructing diffraction patterns from the 21̅1̅0 Bragg peak, show lattice orientation varies along length of wire, while field cross-section is largely unaffected, leaving band structure unperturbed. Diffraction 011̅0 peak reproducibly reconstructed create three-dimensional images associated strains, revealing sharp planar boundaries different crystal phases wurtzite (WZ) contribute charge carrier scattering. Phase retrieval made possible by developing multiangle projection ptychography (maBPP) accommodate nanodiffraction measured at arbitrary overlapping positions multiple angles about eliminating need scan registration angles. The penetrating nature X-ray radiation, together relaxed constraints maBPP, will enable operando imaging devices.