In molecular devices, the importance of interfaces cannot be neglected as they determine charge injection and charge flow and, therefore, the device performance. Herein we report on the interaction of one single layer of Zn tetraphenyl porphyrin with Ag(110) and Si(111) Photoemission are used to study the bonding nature the adsorption geometry as well as the dynamics of electron transfer between the molecules and the metal or semiconductor surfaces. Molecule-substrate charge transfter is driven by the overlap with the molecular pi orbitals in particular, the coupling of the phenyl legs with substrate and the relative excited charge injection are dramatically different for the two surfaces considered.
