Asymmetric MXene/monolayer transition metal dichalcogenide heterostructures for functional applications

A versatile two-dimensional (2D) molecular bilayer heterostructure of asymmetric MXene/monolayer transition metal dichalcogenide (aMXene/mTMDC) with a high interfacial built-in electric field is here simulated, where aMXene is an aMXene with the top or bottom electronegative atom plane of MXene removed. The asymmetric structural design of aMXene leads to a high dipole moment perpendicular to the 2D molecular plane. Although the unpassivated metal atoms in the aMXene are unstable and electropositive, coupling them to the electronegative chalcogenide atoms in an aMXene/mTMDC bilayer resolves this deficiency. The dipole field tunable by the specific composition of aMXene/mTMDC is leveraged to engineer unusual band structures, band alignments, and charge redistribution/injection in the bilayer. The simulated design of several aMXene/mTMDC bilayers for possible use in spintronics, microelectronics/optoelectronics, and catalysis/photocatalysis are shown.