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Highly dense and free-standing InP nanowire structures of vertical orientation were grown by the metalorganic vapor-phase epitaxial technique using colloidal Au nanoparticles as the catalyst. Scanning electron microscopy and transmission electron microscopy showed that the nanowires were single crystalline with 〈111〉 growth direction and of uniform length of about 700 nm, and most of them had diameter in the range of 20–25 nm. Photoluminescence measurements, carried out at room temperature as well as at 77 K, showed a significant blueshift in the peak position compared to bulk InP due to the quantum confinement of the carriers in the nanowires. The successful growth of these nanowires opens up the possibility of realizing various nanoscale devices on the wafer scale in the bottom-up approach.

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Real-time three-dimensional reciprocal space mapping (3D-RSM) measurement during In0.12Ga0.88As/GaAs(001) molecular beam epitaxial growth has been performed to investigate anisotropy in relaxation processes along [110] and [1¯10] directions caused by α and β misfit dislocations (MDs). Anisotropies, strain relaxation, and crystal quality in both directions were simultaneously evaluated via the position and broadness of 022 diffraction in 3D-RSM. In the small-thickness region, strain relaxation caused by α-MDs is higher than that caused by β-MDs, and therefore crystal quality along [110] is worse than that along [1¯10]. Rapid relaxation along both [110] and [1¯10] directions occurs at almost the same thickness. After rapid relaxation, anisotropy in strain relaxation gradually decreases, whereas crystal quality along [1¯10] direction, presumably due to β-MDs, becomes better that along [110] direction and the ratio does not decay with thickness.

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