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Theoretical study of vacuum level shift at the C 6 H 6 /Al(111) interface
Author(s) -
Nakano Yosuke,
Yanagisawa Susumu,
Hamada Ikutaro,
Morikawa Yoshitada
Publication year - 2008
Publication title -
surface and interface analysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.52
H-Index - 90
eISSN - 1096-9918
pISSN - 0142-2421
DOI - 10.1002/sia.2813
Subject(s) - density functional theory , vacuum level , dipole , substrate (aquarium) , charge (physics) , chemistry , interface (matter) , charge density , condensed matter physics , molecular physics , atomic physics , computational chemistry , physics , molecule , quantum mechanics , oceanography , gibbs isotherm , organic chemistry , geology
We have investigated the interface dipole induced at C 6 H 6 /Al(111) by using density functional theory (DFT) within the generalized gradient approximation (GGA). We calculated the vacuum level shift from a simple induced density of interface state (IDIS) model and compared it with that estimated by self‐consistent DFT‐GGA calculations. Both results agree reasonably well with each other in weakly interacting cases, where the charge donation from the highest occupied molecular orbital level dominates, while they deviate from each other in strongly interacting cases, where the lowest unoccupied molecular orbital level starts to be partially filled owing to the back donation from the substrate. Even in weakly interacting cases, the actual charge density distribution is more complex than that assumed in the IDIS model. We discuss the validity and the limitations of the IDIS model to describe the vacuum level shift at organic/metal interfaces. Copyright © 2008 John Wiley & Sons, Ltd.