This thesis deals with growth and characterization of GaAs and InAs nanowires. Today
Au nanoparticle-seeding together with self-catalyzing are the dominating techniques to
grow III-V nanowires with molecular beam epitaxy. In this thesis we instead investigate
the possibility to use Ag as seed particle for growth of GaAs and InAs nanowires. The aim
with the experiments performed has been to conclude whether Ag can be used to nucleate
and grow nanowires on III-V substrates with molecular beam epitaxy. To investigate this
we have performed growths of GaAs nanowires on GaAs(111)B and GaAs(100) substrates
as well as growths of InAs nanowires on InAs(111)B substrates. We have used a wide
range of the basic growth parameters, such as temperature, As-pressure and group III-

ux, in order to nd good growth conditions for the Ag-seeded nanowires. The overall
growths have been evaluated with SEM and, when appropriate, the density and the
vertical yield were obtained. The crystal structures for the grown nanowires have been
investigated with TEM.We have also performed additional growths to further understand
exactly how the nanowire growth proceeds as well as to understand the limitations of using
Ag as a seed particle.
The last chapter presents our results from combining TEM and Raman spectroscopy
to evaluate the possibility to use Raman spectroscopy to nd stacking faults and crystal
defects in GaAs and InAs wurtzite nanowires. We performed TEM on both InAs
nanowires and GaAs nanowires to deduce the stacking fault/crystal defect density and
the results were then compared to Raman spectroscopy on the nanowires.