  We apply molecular beam epitaxy to grow GeSn-nanoparticles on top of
Si-nanopillars patterned onto p-type Si wafers. We use X-ray photoelectron
spectroscopy to confirm a metallic behavior of the nanoparticle surface due to
partial Sn segregation as well as the presence of a superficial Ge oxide. We
report the observation of stable field emission current from the
GeSn-nanoparticles. We prove that field emission can be enhanced by preventing
GeSn nanoparticles oxidation or by breaking the oxide layer through electrical
stress. Finally, we show that GeSn/p-Si junctions have a rectifying behavior.
