title: Ultraflat Au nanoplates as a new building block for molecular electronics.
abstract: We demonstrate the charge transport properties of a self-assembled organic monolayer on Au nanoplates with conductive probe atomic force microscopy (CP-AFM). Atomically flat Au nanoplates, a few hundred micrometers on each side, that have only (111) surfaces, were synthesized using the chemical vapor transport method; these nanoplates were employed as the substrates for hexadecanethiol (HDT) self-assembled monolayers (SAMs). Atomic-scale high-resolution images show (√3 x √3) R30° molecular periodicity, indicating a well-ordered structure of the HDT on the Au nanoplates. We observed reduced friction and adhesion forces on the HDT SAMs on Au nanoplates, compared with Si substrates, which is consistent with the lubricating nature of HDT SAMs. The electrical properties, such as I-V characteristics and current as a function of load, were measured using CP-AFM. We obtained a tunneling decay constant (β) of 0.57 Å(-1), including through-bond (βtb = 0.99 Å(-1)) and through-space (βts = 1.36 Å(-1)) decay constants for the two-pathway model. This indicates that the charge transport properties of HDT SAMs on Au nanoplates are consistent with those on a Au (111) film, suggesting that SAMs on nanoplates can provide a new building block for molecular electronics.
authors.affiliation: Center for Nanomaterials and Chemical Reactions, Institute for Basic Science (IBS), Daejeon 305-701, Korea. Graduate School of EEWS, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 305-701, Korea.
authors.forename: Wooseok
authors.initials: W
authors.lastname: Jeong
authors.forename: Miyeon
authors.initials: M
authors.lastname: Lee
authors.forename: Hyunsoo
authors.initials: H
authors.lastname: Lee
authors.forename: Hyoban
authors.initials: H
authors.lastname: Lee
authors.forename: Bongsoo
authors.initials: B
authors.lastname: Kim
authors.forename: Jeong Young
authors.initials: JY
authors.lastname: Park