Abstract
The atomic arrangements of zinc blende structured GaNxAs1-x nanowires (NWs) surrounded by semiconductor templates are theoretically investigated using empirical interatomic potentials and Monte Carlo simulations. Our calculations demonstrate that the atomic arrangements of GaNxAs1-x NWs strongly depend on nitrogen composition x and substrate lattice constant asub. For a certain nitrogen composition and substrate lattice constant, layered segregation is found in GaNxAs1-x NWs surrounded by templates. On the other hand, surface segregation appears on the side facets of freestanding NWs over the wide range of x and asub. The surface segregation in freestanding NWs originates from the energy difference between Ga-N and Ga-As bonds, which leads to the preference of As atoms at the topmost layer of side facets. These calculated results thus suggest that various novel atomic arrangements in GaNxAs1-x NWs can be realized depending on x and asub which control degree of lattice constraint. [DOI: 10.1380/ejssnt.2014.45]
