Evolution of the structural and electronic properties of thin Bi films on Ge(111)

We have incrementally grown bismuth thin films onto a n-doped Ge(111) substrate. Low energy electron diffraction reveals that the first Bi atomic layer is characterized by the $(\sqrt{3}\times \sqrt{3})R{30}^{\circ }$ reconstruction. By angle-resolved photoemission spectroscopy we observe Rashba-split bands that do not cross the Fermi level. At higher coverages, where a Rashba type of splitting should still be present, the density of occupied states close to the Fermi energy gradually increases, while extra diffraction spots, related to Bi(110) islands, appear. (paper)