title: Thickness Considerations of Two-Dimensional Layered Semiconductors for Transistor Applications.
abstract: Layered two-dimensional semiconductors have attracted tremendous attention owing to their demonstrated excellent transistor switching characteristics with a large ratio of on-state to off-state current, Ion/Ioff. However, the depletion-mode nature of the transistors sets a limit on the thickness of the layered semiconductor films primarily determined by a given Ion/Ioff as an acceptable specification. Identifying the optimum thickness range is of significance for material synthesis and device fabrication. Here, we systematically investigate the thickness-dependent switching behavior of transistors with a wide thickness range of multilayer-MoS2 films. A difference in Ion/Ioff by several orders of magnitude is observed when the film thickness, t, approaches a critical depletion width. The decrease in Ion/Ioff is exponential for t between 20 nm and 100 nm, by a factor of 10 for each additional 10 nm. For t larger than 100 nm, Ion/Ioff approaches unity. Simulation using technical computer-aided tools established for silicon technology faithfully reproduces the experimentally determined scaling behavior of Ion/Ioff with t. This excellent agreement confirms that multilayer-MoS2 films can be approximated as a homogeneous semiconductor with high surface conductivity that tends to deteriorate Ion/Ioff. Our findings are helpful in guiding material synthesis and designing advanced field-effect transistors based on the layered semiconductors.
authors.affiliation: State Key Laboratory of ASIC and System, School of Information Science and Technology, Fudan University, Shanghai 200433, China.|State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem &Information Technology, Chinese Academy of Sciences, Changning Road 865, Shanghai 200050, China.
authors.forename: Youwei
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of ASIC and System, School of Information Science and Technology, Fudan University, Shanghai 200433, China.
authors.forename: Hui
authors.initials: H
authors.lastname: Li
authors.affiliation: State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem &Information Technology, Chinese Academy of Sciences, Changning Road 865, Shanghai 200050, China.
authors.forename: Haomin
authors.initials: H
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem &Information Technology, Chinese Academy of Sciences, Changning Road 865, Shanghai 200050, China.
authors.forename: Hong
authors.initials: H
authors.lastname: Xie
authors.affiliation: State Key Laboratory of ASIC and System, School of Information Science and Technology, Fudan University, Shanghai 200433, China.
authors.forename: Ran
authors.initials: R
authors.lastname: Liu
authors.affiliation: Solid-State Electronics, The Ångström Laboratory, Uppsala University, Uppsala Box 534, SE-751 21, Sweden.
authors.forename: Shi-Li
authors.initials: SL
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of ASIC and System, School of Information Science and Technology, Fudan University, Shanghai 200433, China.
authors.forename: Zhi-Jun
authors.initials: ZJ
authors.lastname: Qiu