First-principle investigation 3,4-ethylenedioxythiophene molecule adsorption on Cu(110)-(2 x 1)O surface

摘要

The adsorption of 3,4-ethylenedioxythiophene (EDOT) on Cu(110)-(2 x 1)O was investigated by first-principles density functional theory (DFT). We found that, at low EDOT coverage, the most favorable adsorbing geometry is the thiophene ring of EDOT parallel to the Cu (1 (1) over bar2) and molecule is upright rather than lying. With the increasing of EDOT coverage, the dimer and tetramer can form by new forming C = C and C-Cu bonds. The dimer and tetramer were neither cis synthesized recently nor traditional anti structure. On the contrary, the EDOT was alternative tilted and formed a zigzag-like molecule arrangement. The binding mechanism of EDOT and substrate was clarified by density of state (DOS) analysis and charge density difference (CDD) calculations. The strong molecule-substrate interaction was confirmed by high adsorption energy for the most stable adsorbing geometry. In addition, the STM images were also simulated by evaluating the contribution of local density of state near fermi energy level. (C) 2017 Elsevier B.V. All rights reserved.