  Studying the reason, why single-layer molybdenum disulfide (MoS$_2$) appears
to fall short of its promising potential in flexible nanoelectronics, we found
that the nature of contacts plays a more important role than the semiconductor
itself. In order to understand the nature of MoS$_2$/metal contacts, we
performed ab initio density functional theory calculations for the geometry,
bonding and electronic structure of the contact region. We found that the most
common contact metal (Au) is rather inefficient for electron injection into
single-layer MoS$_2$ and propose Ti as a representative example of suitable
alternative electrode materials.
