Title: Heterogeneous nucleation of catalyst-free InAs nanowires on silicon,
Abstract: We report on the heterogeneous nucleation of catalyst-free InAs nanowires on
Si (111) substrates by chemical beam epitaxy. We show that nanowire nucleation
is enhanced by sputtering the silicon substrate with energetic particles. We
argue that particle bombardment introduces lattice defects on the silicon
surface that serve as preferential nucleation sites. The formation of these
nucleation sites can be controlled by the sputtering parameters, allowing the
control of nanowire density in a wide range. Nanowire nucleation is accompanied
by unwanted parasitic islands, but by careful choice of annealing and growth
temperature allows to strongly reduce the relative density of these islands and
to realize samples with high nanowire yield.