11-05
R.E. Algra, M.A. Verheijen,
L.F. Feiner, G.G.W. Immink,
W.J.P. van Enckevort, E. Vlieg,
E.P.A.M. Bakkers,
The role of surface energies and chemical potential during nanowire growth,
Nano Lett. 11 (2011) 1259-1264
Abstract
We present an approach to quantitatively determine the magnitudes and
the variation of the chemical potential in the droplet (Delta mu), the solid
liquid (gamma(SL)) and the liquid-vapor (gamma(LV)) interface energies upon
variation of the group III partial pressure during vapor-liquid-solid growth of
nanowires. For this study, we use GaP
twinning superlattice nanowires.
We show that gamma(LV) is the quantity that is most sensitive to the Ga partial pressure (p(Ga)), its
dependence on p(Ga) being three to four times as
strong as that of gamma(SL) or Delta mu, and that as a consequence the surface
energies are as important in determining the twin density as the chemical
potential. This unexpected result implies that surfactants could be used during
nanowire growth to engineer the nanowire
defect structure and crystal structure.