Dependence of the band structure of C60 monolayers on molecular orientations and doping observed by angle resolved photoemission

We present angle resolved photoemission studies of C60 monolayers deposited on Ag surfaces. The electronic structure of these monolayers is derived from the partial filling of the narrow, 6-fold degenerated, C60 conduction band. By comparing the band structure in two monolayers deposited, respectively, on Ag(111) and Ag(100), we show that the molecular degree of freedom, in this case the relative orientations between C60 molecules, is essential to describe the band structure. We further show that the evolution of the band as a function of doping does not follow a rigid band-filling picture. Phase separation is observed between a metallic and an insulating phase, which might be a result of strong correlations.