title: Ferroelectricity in Covalently functionalized Two-dimensional Materials: Integration of High-mobility Semiconductors and Nonvolatile Memory.
abstract: Realization of ferroelectric semiconductors by conjoining ferroelectricity with semiconductors remains a challenging task because most present-day ferroelectric materials are unsuitable for such a combination due to their wide bandgaps. Herein, we show first-principles evidence toward the realization of a new class of two-dimensional (2D) ferroelectric semiconductors through covalent functionalization of many prevailing 2D materials. Members in this new class of 2D ferroelectric semiconductors include covalently functionalized germanene, and stanene (Nat. Commun. 2014, 5, 3389), as well as MoS2monolayer (Nat. Chem. 2015, 7, 45), covalent functionalization of the surface of bulk semiconductors such as silicon (111) (J. Phys. Chem. B 2006, 110 , 23898), and the substrates of oxides such as silica with self-assembly monolayers (Nano Lett. 2014, 14, 1354). The newly predicted 2D ferroelectric semiconductors possess high mobility, modest bandgaps, and distinct ferroelectricity that can be exploited for developing various heterostructural devices with desired functionalities. For example, we propose applications of the 2D materials as 2D ferroelectric field-effect transistors with ultrahigh on/off ratio, topological transistors with Dirac Fermions switchable between holes and electrons, ferroelectric junctions with ultrahigh electro-resistance, and multiferroic junctions for controlling spin by electric fields. All these heterostructural devices take advantage of the combination of high-mobility semiconductors with fast writing and nondestructive reading capability of nonvolatile memory, thereby holding great potential for the development of future multifunctional devices.
authors.affiliation: School of Physics and Wuhan National High Magnetic Field Center, Huazhong University of Science and Technology , Wuhan 430074, China.
authors.forename: Menghao
authors.initials: M
authors.lastname: Wu
authors.affiliation: Department of Physics, Southeast University , Nanjing 211189, China.
authors.forename: Shuai
authors.initials: S
authors.lastname: Dong
authors.affiliation: School of Physics and Wuhan National High Magnetic Field Center, Huazhong University of Science and Technology , Wuhan 430074, China.
authors.forename: Kailun
authors.initials: K
authors.lastname: Yao
authors.affiliation: Laboratory of Solid State Microstructures, Nanjing University , Nanjing 210093, China.
authors.forename: Junming
authors.initials: J
authors.lastname: Liu
authors.affiliation: Department of Chemistry, University of Nebraska-Lincoln , Lincoln, Nebraska 68588, United States.|Collaborative Innovation Center of Chemistry for Energy Materials, University of Science and Technology of China , Hefei, Anhui 230026, China.
authors.forename: Xiao Cheng
authors.initials: XC
authors.lastname: Zeng
keywords: Ferroelectric semiconductors; covalent functionalization; multifunctional devices