摘要
Metal-organic contacts are keys to define the functionalities of hybrid structures, but orbital hybridization at interfaces has made rationalizing their behavior a challenging task. Here, we examined Fe/C 60 and Ni/C 60 bilayers with X-ray absorption spectra to study the nature of orbital hybridization and the possible correlation with metal penetration. Depositing Fe or Ni on C 60 films of sub-nanometer thickness to emulate interfaces, we found that both bilayers show evidence of not only d-π hybridization and metal penetration but also a deeper Ni penetration. The carbon K-edge spectra recorded from C 60 films indicate that the deeper Ni penetration is accompanied by a larger donation of electrons from Ni to C 60 . This finding of hybridization-modulated metal penetration is somewhat counterintuitive but is consistent with a scenario of metal-C 60 hybridization competing with metal-metal aggregation. A stronger Ni-C 60 hybridization could result in smaller Ni clusters and a greater probability of penetration through the interstitial space between C 60 molecules. We conclude that metal penetration can be regulated with orbital hybridization between metal and C 60 .