Periodically Changing Morphology of the Growth Interface in Si, Ge, and GaP Nanowires
Date of this Version7-6-2011
Periodically Changing Morphology of the Growth Interface in Si, Ge, and GaP Nanowires C.-Y. Wen, J. Tersoff, K. Hillerich, M. C. Reuter, J. H. Park, S. Kodambaka, E. A. Stach, and F. M. Ross Phys. Rev. Lett. 107, 025503 – Published 6 July 2011
Nanowire growth in the standard < 111 > direction is assumed to occur at a planar catalyst-nanowire interface, but recent reports contradict this picture. Here we show that a nonplanar growth interface is, in fact, a general phenomenon. Both III-V and group IV nanowires show a distinct region at the trijunction with a different orientation whose size oscillates during growth, synchronized with step flow. We develop an explicit model for this structure that agrees well with experiment and shows that the oscillations provide a direct visualization of catalyst supersaturation. We discuss the implications for wire growth and structure.
Nanoscience and Nanotechnology