First-principles Theoretical Study of Organic-metal Interfaces

Abstract

In this article, we review recent progress in theor. studies on the electronic properties of organic/metal interfaces, especially, on the origin of the interface dipoles. We first discuss the effect of the interface dipole on the charge injection barriers at organic/metal interfaces. Then, we observe the importance of the interface structure, especially, the organic-metal distances in physisorption systems. In this case, the exptl. observed substrate dependence of the interface dipole can be attributed mainly to the difference in the organic-metal distance. In the case of chemisorption systems, the induced d. of interface states tends to pin the Fermi level relative to the HOMO and LUMO levels of mols. We also discuss the importance of the alignment of mol. permanent dipoles in the case of Alq3/metal interfaces, which are relevant to organic light emitting devices.