Cage relaxation effects on the local density of states in a C60 derivative

Abstract A (6-6) bonded fulleroid C 60 (NH(CHCOOCH 3 ) 2 ) has been deposited on a GeS(001) crystal by molecular beam expitaxy (MBE). XPS and LEED experiments suggest that the molecules are close packed in a (111) plane with the tail pointing to the vacuum. The local density of states of the film has been investigated by direct and inverse photoemission spectroscopies. Cage relaxation effects induced by (6-6) bond breaking has been localized in the π states around the HOMO-LUMO gap as evidenced by a 0.5 and 0.8 eV shift of the HOMO and LUMO feature towards higher and lower binding energies, respectively.