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GaP/GaAsP/GaP segmented nanowires were grown by gas source molecular beam epitaxy on silicon (111) substrates. The nanowires were grown by the vapour-liquid-solid process using Au nanoparticles. Transmission electron microscopy and energy dispersive x-ray spectroscopy indicated that the wires had wurtzite crystal structure with a core-multishell heterostructure. Stacking faults along the wire were removed after the growth-interrupted interfaces, indicating the potential for defect-free nanowires.

Atomic-resolution imaging in the scanning transmission electron microscope (STEM) constitutes a powerful tool for nanostructure characterization. Here, we demonstrate the quantitative interpretation of atomic-resolution high-angle annular dark-field (ADF) STEM images using an approach that does not rely on adjustable parameters. We measure independently the instrumental parameters that affect sub-0.1 nm-resolution ADF images, quantify their individual and collective contributions to the image intensity, and show that knowledge of these parameters enables a quantitative interpretation of the absolute intensity and contrast across all accessible spatial frequencies. The analysis also provides a method for the in-situ measurement of the STEM’s effective source distribution.