title: Thickness scaling effect on interfacial barrier and electrical contact to two-dimensional MoS2 layers.
abstract: Understanding the interfacial electrical properties between metallic electrodes and low-dimensional semiconductors is essential for both fundamental science and practical applications. Here we report the observation of thickness reduction induced crossover of electrical contact at Au/MoS2 interfaces. For MoS2 thicker than 5 layers, the contact resistivity slightly decreases with reducing MoS2 thickness. By contrast, the contact resistivity sharply increases with reducing MoS2 thickness below 5 layers, mainly governed by the quantum confinement effect. We find that the interfacial potential barrier can be finely tailored from 0.3 to 0.6 eV by merely varying MoS2 thickness. A full evolution diagram of energy level alignment is also drawn to elucidate the thickness scaling effect. The finding of tailoring interfacial properties with channel thickness represents a useful approach controlling the metal/semiconductor interfaces which may result in conceptually innovative functionalities.
authors.affiliation: WPI Center for Materials Nanoarchitechtonics and ‡International Center for Young Scientist, National Institute for Materials Science , Tsukuba, Ibaraki 305-0044, Japan.
authors.forename: Song-Lin
authors.initials: SL
authors.lastname: Li
authors.forename: Katsuyoshi
authors.initials: K
authors.lastname: Komatsu
authors.forename: Shu
authors.initials: S
authors.lastname: Nakaharai
authors.forename: Yen-Fu
authors.initials: YF
authors.lastname: Lin
authors.forename: Mahito
authors.initials: M
authors.lastname: Yamamoto
authors.forename: Xiangfeng
authors.initials: X
authors.lastname: Duan
authors.forename: Kazuhito
authors.initials: K
authors.lastname: Tsukagoshi
keywords: Schottky barrier; chalcogenide; electrical contact; field-effect transistor; quantum confinement; two-dimensional material