Showing papers by "Yun-Peng Wang published in 2012"

Adsorption of tris(8-hydroxyquinoline)aluminum molecules on cobalt surfaces

Abstract: We studied the adsorption of tris(8-hydroxyquinoline) aluminum (Alq(3)) molecules on cobalt surfaces using density functional theory with the generalized gradient approximation. The van der Waals interaction between Alq(3) molecules and cobalt surfaces was included by the dispersion correction. Magnetization of Alq(3) molecules, adsorption energies, and bonding energies were obtained for smooth and defective surfaces and for various molecule-surface configurations. Electronic structures were analyzed for states that are relatively stable. We found that both the permanent electric dipole of Alq(3) molecules and the charge redistribution near the interface contribute to the interface dipole, and the interface dipole due to charge redistribution is important to determine the work function of a Co/Alq(3) surface. Our calculated energy-level alignment at interfaces is consistent with experimental observations.