Full characterization of the interface between the organic semiconductor copper phthalocyanine and gold

We present a study of the interface properties of the molecular organic semiconductor copper phthalocyanine (CuPC) on single crystalline as well as polycrystalline Au using photoemission spectroscopy. Despite the different orientation of the molecules on the two substrates, the observed energy level alignment is identical. We observe the formation of an interface dipole while band bending is very small. In addition, we have carried out complementary studies of the CuPC/GeS(001) interface to pin down photoemission final state effect contributions to the observed energy level shifts.