Band dispersion effects on the Cu 2p(3/2) X-ray photoemission core lines in cuprates

The effect of band dispersion on the Cu 2p X-ray photoemission core line in cuprates is studied and a discussion is proposed on the interplay between the local aspects of the photoemission event and the long-range properties of the solid. The Cu 2p(3/2) core line emission of CuGeO3 and Bi2Sr2CaCu2O8 calculated using a parametrized configuration interaction impurity cluster model is compared with the experimental data. It is shown that by explicitly including into the model the valence band density of states, the fine structure of the Cu 2p(3/2) main line can be reproduced and the main line width increases with the Cu 3d band dispersion.