title: Controllable Schottky barriers between MoS2 and permalloy.
abstract: MoS2 is a layered two-dimensional material with strong spin-orbit coupling and long spin lifetime, which is promising for electronic and spintronic applications. However, because of its large band gap and small electron affinity, a considerable Schottky barrier exists between MoS2 and contact metal, hindering the further study of spin transport and spin injection in MoS2. Although substantial progress has been made in improving device performance, the existence of metal-semiconductor Schottky barrier has not yet been fully understood. Here, we investigate permalloy (Py) contacts to both multilayer and monolayer MoS2. Ohmic contact is developed between multilayer MoS2 and Py electrodes with a negative Schottky barrier, which yields a high field-effect mobility exceeding 55 cm(2)V(-1)s(-1) at low temperature. Further, by applying back gate voltage and inserting different thickness of Al2O3 layer between the metal and monolayer MoS2, we have achieved a good tunability of the Schottky barrier height (down to zero). These results are important in improving the performance of MoS2 transistor devices; and it may pave the way to realize spin transport and spin injection in MoS2.
authors.affiliation: State Key Laboratory of Surface Physics and Department of Physics, Fudan University, Shanghai 200433, China.
authors.forename: Weiyi
authors.initials: W
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Surface Physics and Department of Physics, Fudan University, Shanghai 200433, China.
authors.forename: Yanwen
authors.initials: Y
authors.lastname: Liu
authors.affiliation: State Key Laboratory of Surface Physics and Department of Physics, Fudan University, Shanghai 200433, China.
authors.forename: Lei
authors.initials: L
authors.lastname: Tang
authors.affiliation: State Key Laboratory of Surface Physics and Department of Physics, Fudan University, Shanghai 200433, China.
authors.forename: Yibo
authors.initials: Y
authors.lastname: Jin
authors.affiliation: State Key Laboratory of Surface Physics and Department of Physics, Fudan University, Shanghai 200433, China.
authors.forename: Tongtong
authors.initials: T
authors.lastname: Zhao
authors.affiliation: State Key Laboratory of Surface Physics and Department of Physics, Fudan University, Shanghai 200433, China.
authors.forename: Faxian
authors.initials: F
authors.lastname: Xiu