title: Is there a Au-S bond dipole in self-assembled monolayers on gold?
abstract: Self-assembled monolayers (SAMs) of functionalized thiols are widely used in organic (opto)electronic devices to tune the work function, Phi, of noble-metal electrodes and, thereby, to optimize the barriers for charge-carrier injection. The achievable Phi values not only depend on the intrinsic molecular dipole moment of the thiols but, importantly, also on the bond dipole at the Au-S interface. Here, on the basis of extensive density-functional theory calculations, we clarify the ongoing controversy regarding the existence, the magnitude, and the nature of that bond dipole.
authors.affiliation: Department of Chemistry, Tsinghua University, 100084 Beijing, PR China.
authors.forename: Linjun
authors.initials: L
authors.lastname: Wang
authors.forename: Gerold M
authors.initials: GM
authors.lastname: Rangger
authors.forename: Zhongyun
authors.initials: Z
authors.lastname: Ma
authors.forename: Qikai
authors.initials: Q
authors.lastname: Li
authors.forename: Zhigang
authors.initials: Z
authors.lastname: Shuai
authors.forename: Egbert
authors.initials: E
authors.lastname: Zojer
authors.forename: Georg
authors.initials: G
authors.lastname: Heimel