  We demonstrate how self-assembled monolayers of aromatic molecules on copper
substrates can be converted into high-quality single-layer graphene using
low-energy electron irradiation and subsequent annealing. We characterize this
two-dimensional solid state transformation on the atomic scale and study the
physical and chemical properties of the formed graphene sheets by complementary
microscopic and spectroscopic techniques and by electrical transport
measurements. As substrates we successfully use Cu(111) single crystals and the
technologically relevant polycrystalline copper foils.
