X-ray Structural Analysis of Core–Shell GaPNAs/GaP Nanowires Grown on a Si(111) Substrate

The development of nanowire growth technology based on the GaPNAs solid solution is of interest for modern photonics. A structural analysis of core–shell GaPNAs/GaP nanowires grown on a Si(111) substrate using the self-catalyzed molecular beam epitaxy method has been performed. Transmission electron microscopy has shown the formation of a core and a composite shell in the nanowire body. The twinned sphalerite phase and non-twinned wurtzite phase have been determined. Scanning electron microscopy has revealed the formation of a continuous layer of islands on the sample surface when a nitrogen flow is turned on, which confirms embedding of nitrogen into the grown structures. It was impossible to separate the diffraction reflections of the core and shell of both the sphalerite and wurtzite phases using X-ray diffraction analysis with reciprocal space mapping. The average lattice constant of the sphalerite phase was found to be 5.458 ± 0.005 Å, as well as the average lattice parameters of the wurtzite phase: a = 3.87 ± 0.01 and c = 6.28 ± 0.01 Å. The fact that the phase lattice constants are indistinguishable in the nanowires confirms the possibility of creating high-quality low-defect GaPNAs/GaP nanowires.