A Vertical Hybrid van der Waals Ferroelectric Material for Nonvolatile Memory

Two-dimensional (2D) ferroelectric materials can form
an atomically
thin dipole layer that can influence the electronic properties of
a hybrid layered structure composed of a ferroelectric layer and a
transition-metal dichalcogenide (TMDC). In this work, we investigate
the ability of a 2D ferroelectric material, CuBiP2Se6, to transition between two dipolar states as a potential
nonvolatile memory component. We propose a 2D heterostructure as a
tunable p–n junction composed of a TDMC layer and a 2D ferroelectric
layer, wherein the TMDC layer acts as the electron acceptor and CuBiP2Se6 acts as the electron donor across the heterostructure.
Using density functional theory, we find that the ferroelectric-MoSe2 bilayer transitions between an indirect type II bandgap and
a direct type I bandgap, as a function of the change in the direction
of the electric dipole in the ferroelectric layer. The electric field
can lock the bandgap of the bilayer in one of two states, thus operating
as a switchable ferroelectric memory device. Our work presents new
hybrid bilayer materials that could be used in the construction of
neuromorphic components.