  The implementation of graphene in semiconducting technology requires the
precise knowledge about the graphene-semiconductor interface. In our work the
structure and electronic properties of the graphene/$n$-Ge(110) interface are
investigated on the local (nm) and macro (from $\mu\mathrm{m}$ to mm) scales
via a combination of different microscopic and spectroscopic surface science
techniques accompanied by density functional theory calculations. The
electronic structure of freestanding graphene remains almost completely intact
in this system, with only a moderate $n$-doping indicating weak interaction
between graphene and the Ge substrate. With regard to the optimization of
graphene growth it is found that the substrate temperature is a crucial factor,
which determines the graphene layer alignment on the Ge(110) substrate during
its growth from the atomic carbon source. Moreover, our results demonstrate
that the preparation routine for graphene on the doped semiconducting material
($n$-Ge) leads to the effective segregation of dopants at the interface between
graphene and Ge(110). Furthermore, it is shown that these dopant atoms might
form regular structures at the graphene/Ge interface and induce the doping of
graphene. Our findings help to understand the interface properties of the
graphene-semiconductor interfaces and the effect of dopants on the electronic
structure of graphene in such systems.
