First-Principles Studies of the Tunneling Properties through Ferroelectric/Ferromagnetic van der Waals Heterostructures

Abstract

Two-dimensional (2D) ferroelectric/ferromagnetic van der Waals heterostructures (vdWHs) possess more than one ferric order and coupling effect, showing great application potential in information-processing devices. In the present work, we construct a graphene/In2Se3/CrI3/graphene vdWH to investigate its electronic and tunneling transport properties using first-principles calculations and the nonequilibrium Green function–density functional theory method. Two states are obtained in the vdWH, and they can be switched by the reversal of the polarization in the In2Se3 layer. One state shows nearly 100% spin-polarization around the Fermi level and another state with the opposite polarization direction shows no spin-polarization. Furthermore, in the transport property calculations, near-hole-conducting properties in one state and near-electron-conducting properties in another state are discovered, and they can be converted to each other with the polarization in In2Se3 reversed. Our results provide a new route to build an electric device in the nanoscale and to explore new potential applications of vdWHs.

Abnormal Evolution of a Layered Structure and Band Gap in AgInP2S6 under Compression

“…In recent work, the unique electronic and optical properties have mainly been studied in bulk metal phosphors, especially in this lamellar chalcogenophosphate M I M II P 2 X 6 . For example, the new layered material CuInP 2 S 6 has four polarization states at the same time; because of the unique layered structure, Cu ions can move in the layer under a short time and weak electric field to realize the ferroelectric conversion between the layers. − CuCrP 2 S 6 has different convergence points in the antiferroelectric and paraelectric phases, and electric field can be used to drive ferroelectricity in a single layer or even several layers. , Three phase transitions were observed at low temperatures (30.45, 154.96, and 185.92 K). The origin of phase transition is the magnetic origin caused by the spin of chromium and the positional disorder of Cu+ ions .…”

Tunable Schottky barriers and magnetoelectric coupling driven by ferroelectric polarization reversal of In2Se3/MnI3 multiferroic heterostructures: A first-principles study

“…S1 and Table S1 (see the Supplementary material). The equilibrium interlayer distances between MnI3 and In2Se3 in three stacking modes range from 3.22 Å to 3.92 Å, which are comparable to that of CrI3/In2Se3 34,39 . Meanwhile, their interlayer distances are larger than the sum of the covalent radii of I and Se atoms, suggesting that the interlayer coupling of MnI3/In2Se3 vdWHs is chiefly governed by van der Waals interactions.…”

“…To date, theoretical studies have proved that switching polarization direction of In2Se3 has achieved effective regulation of 2D multiferroic heterostructures, such as (1) modulating the magnetic moments in Cr2Ge2Te6/In2Se3 9 and Fe3GeTe2/In2Se3 35 , (2) adjusting the easy magnetization axis in CrI3/In2Se3 26 and VBi2Te4/In2Se3 31 , (3) triggering an interlayer magnetic phase transition between FM and antiferromagnetic (AFM) states in FeI2/In2Se3 32 and bilayer-CrI3/In2Se3 34 , (4) influencing valley polarization in the HfN2/CrI3/In2Se3 vdWH 37 , and (5) affecting spin polarization states and transport properties in the Graphene/In2Se3/CrI3/Graphene vdWH 39 . The pioneering studies highlight that the In2Se3 monolayer can provide a nonvolatile electric field to regulate the magnetic and magnetoelectric coupling of 2D multiferroic heterostructures.…”

Controlling the Electro-Optical Properties of an AlSb Monolayer with a DLHC Structure through Phosphorus Alloying: A DFT Study

“…Two-dimensional (2D) van der Waals (vdW) materials are classified into families of artificially structured materials that possess strong covalent bonds in the electronvolt-per-atom (eV/atom) range within the plane and anisotropic bonds − with weak vdW bonding between layers. These new classes of materials can be considered an excellent choice for use in novel semiconductors, , nanosensors, field-effect transistors, and lithium-ion batteries. − A broad range of vdW materials such as graphene, , despite its superior optoelectronic properties, suffer from insufficient bandgap widening and degraded carrier mobility .…”