title: Interface electronic structures of reversible double-docking self-assembled monolayers on an Au(111) surface.
abstract: Double-docking self-assembled monolayers (DDSAMs), namely self-assembled monolayers (SAMs) formed by molecules possessing two docking groups, provide great flexibility to tune the work function of metal electrodes and the tunnelling barrier between metal electrodes and the SAMs, and thus offer promising applications in both organic and molecular electronics. Based on the dispersion-corrected density functional theory (DFT) in comparison with conventional DFT, we carry out a systematic investigation on the dual configurations of a series of DDSAMs on an Au(111) surface. Through analysing the interface electronic structures, we obtain the relationship between single molecular properties and the SAM-induced work-function modification as well as the level alignment between the metal Fermi level and molecular frontier states. The two possible conformations of one type of DDSAM on a metal surface reveal a strong difference in the work-function modification and the electron/hole tunnelling barriers. Fermi-level pinning is found to be a key factor to understand the interface electronic properties.
authors.affiliation: Key Laboratory of Organic OptoElectronics and Molecular Engineering, Department of Chemistry, Tsinghua University, , Beijing 100084, People's Republic of China.
authors.forename: Tian
authors.initials: T
authors.lastname: Zhang
authors.forename: Zhongyun
authors.initials: Z
authors.lastname: Ma
authors.forename: Linjun
authors.initials: L
authors.lastname: Wang
authors.forename: Jinyang
authors.initials: J
authors.lastname: Xi
authors.forename: Zhigang
authors.initials: Z
authors.lastname: Shuai
keywords: dispersion-corrected density functional theory; interface electronic structure; self-assembled monolayers; work function