High resolution photoemission spectroscopy: Evidence for strong chemical interaction between Mg and 3,4,9,10-perylene-tetracarboxylic dianhydride

The interface formation between Mg and 3,4,9,10-perylene-tetracarboxylic dianhydride (PTCDA) was investigated by high resolution soft x-ray photoemission spectroscopy. The interface chemistry was obtained after fitting the core level spectra as a function of Mg thickness. At the initial stage of deposition, a strong chemical interaction between Mg and the single bonded oxygen atoms of PTCDA is observed leading to the formation of MgO and a modified organic molecule. Based on the experimental evidence, the molecular structure of the modified molecule is proposed. Moreover, the changes observed in the measured C-1s core level spectra are supported by density functional theory calculations. (c) 2006 American Institute of Physics.