Epitaxial DySi_2 nanowire formation on stepped Si(111)

摘要

We report the growth of epitaxial DySi_2 nanowires (NW) with a single orientation on miscut Si(111). Using high-resolution electron microscopy, we determine that the islands are hexagonal DySi_2 with orientation DySi_2(0001)‖Si(111), corresponding to a near-perfect lattice match. The NW islands develop extended defects that correlate perfectly with individual step bunches at the buried interface, produced during growth. By contrast, islands grown on step-free substrates develop a broad, two-dimensional shape with no defects. We suggest that the NW shape results from the energy cost of extended defects, which inhibits growth across step edges.