Electron affinity of the diamond (100) surface changed by adsorption of C60

Abstract We investigate the electron affinity change of the hydrogen-terminated diamond (100) surface with adsorption of C 60 by means of ultraviolet photoelectron spectroscopy. X-ray photoelectron spectroscopy permits one to distinguish between the two materials of the same element and shows that there is no chemical bonding between the C 60 molecules and the diamond substrate. The diamond (100)–(2×1):H surface presents a true negative electron affinity (NEA) of −1.1 eV and a high intensity NEA peak with a full width of half maximum of 250 meV. After successive evaporation of C 60 the NEA values as well as the NEA peak decrease.