Initial stages of metal/organic semiconductor interface formation

We have used photoelectron spectroscopies to study the metal/organic semiconductor interfaces formed by depositing three different metal-quinolate derivatives on Ag, with the goal of better understanding the initial stages of interface formation. We find very consistent results at all three interfaces, which exhibit strong energy level shifts within the first molecular layer, followed by a nearly flat-band condition. These results were analyzed in the context of the interface dipole and band-bending models. We conclude that the interface dipole model, extended to account for the differences in polarization screening in the first molecular layer, most accurately describes our findings. In this article we present the most thorough description of the early stages of metal/molecular organic semiconductor interfaces to date. (C) 2000 American Institute of Physics. [S0021-8979(00)02814-0].