Influence of the Fluorination of CoPc on the Interfacial Electronic Structure of the Coordinated Metal Ion

Abstract

Interface properties of CoPc and CoPcF16 on Cu-intercalated graphene/Ni(111) were investigated by X-ray photoemission spectroscopy (XPS), ultraviolet photoemission spectroscopy (UPS), and X-ray absorption spectroscopy (XAS). We show that a charge transfer from graphene/Ni(111) to the Co ion of CoPc can be significantly reduced by Cu-intercalation of graphene, resulting in a partial decoupling of graphene from the Ni(111) substrate. This is not the case for CoPcF16 on Cu-intercalated graphene/Ni(111). Possible reasons and charge transfer channels are discussed. The comparison to CoPcF16 on the almost fully decoupled Au-intercalated graphene/Ni(111) suggests that the graphene-substrate coupling in the case of Cu-intercalation remains still significant.