Periodically changing morphology of the growth interface in Si, Ge, and GaP nanowires
Journal
Physical Review Letters
Journal Volume
107
Journal Issue
2
Date Issued
2011
Author(s)
Wen, C.-Y.
Tersoff, J.
Hillerich, K.
Reuter, M.C.
Park, J.H.
Kodambaka, S.
Stach, E.A.
Ross, F.M.
Abstract
Nanowire growth in the standard 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.
Type
journal article