Characterizing 3D Defect Networks in GaAs Nanowires using Coherent X-ray Diffractive Imaging

Bragg Coherent Diffractive Imaging (BCDI) is a sophisticated X-ray technique proficient in nondestructively probing internal strain fields, defects, and 3D networks of dislocations within crystalline samples. Capitalizing on the coherent properties of X-rays, it attains nanoscale resolution, making it invaluable for materials science. In our recent study, we employed BCDI to investigate an as-grown GaAs nanowire, a material paramount in the semiconductor realm due to its optimal direct bandgap for photovoltaic applications and diverse morphological adaptability. Our analysis unveiled a multifaceted 3D network of dislocations and stacking faults, intriguingly manifesting a core-shell architecture in the wire without necessitating multiple growth phases or external treatments. This in-depth characterization elucidates the inherent defects and corresponding long-range strain, accentuating BCDI's prowess in achieving picometer strain resolution and detecting a broad spectrum of defects. This research underscores the potential of BCDI for holistic 3D analysis of nanostructured materials.