Activating ferroelectricity in two-dimensional(2D)bilayer materials is essential for enabling nonvolatile memory and logic functionalities.While interlayer sliding driven by van der Waals interactions can break invers...Activating ferroelectricity in two-dimensional(2D)bilayer materials is essential for enabling nonvolatile memory and logic functionalities.While interlayer sliding driven by van der Waals interactions can break inversion symmetry,achieving out-of-plane(OOP)polarization through this mechanism remains challenging in highly symmetric 2D materials—particularly those that are centrosymmetric,such as graphene,hexagonal boron nitride(hBN),and transition metal dichalcogenides(TMDs).Here,we propose a general strategy to activate OOP ferroelectricity by intercalating inert atoms into the interlayer space.Using bilayer graphene,hBN,and MoS_(2)as model systems,we reveal that such intercalation lowers the symmetry from nonpolar D_(3d)to polar C_(3v),enabling reversible polarization switching via lateral displacement of the intercalants.This resulting semi-sliding ferroelectricity preserves the structural and electronic integrity of the host materials,and features ultralow switching barriers along with atomic-scale dipole control—where each intercalated atom acts as an independent,reversible memory bit.Importantly,the polarization magnitude scales linearly with the electrostatic potential difference across the bilayer,providing a quantitative and tunable design rule.Our findings establish a universal and material-agnostic framework for realizing low-power,ultrahighdensity 2D ferroelectric devices on otherwise nonpolar platforms.展开更多
基金supported by the National Natural Science Foundation of China(No.12504101)the High-level Talent Research Start-up Project Funding of Henan Academy of Sciences(Project No.241827153)the Fundamental Research Fund of Henan Academy of Sciences(Project No.20250627003).We thank the Core Facility of Wuhan University for providing the computational resources.
文摘Activating ferroelectricity in two-dimensional(2D)bilayer materials is essential for enabling nonvolatile memory and logic functionalities.While interlayer sliding driven by van der Waals interactions can break inversion symmetry,achieving out-of-plane(OOP)polarization through this mechanism remains challenging in highly symmetric 2D materials—particularly those that are centrosymmetric,such as graphene,hexagonal boron nitride(hBN),and transition metal dichalcogenides(TMDs).Here,we propose a general strategy to activate OOP ferroelectricity by intercalating inert atoms into the interlayer space.Using bilayer graphene,hBN,and MoS_(2)as model systems,we reveal that such intercalation lowers the symmetry from nonpolar D_(3d)to polar C_(3v),enabling reversible polarization switching via lateral displacement of the intercalants.This resulting semi-sliding ferroelectricity preserves the structural and electronic integrity of the host materials,and features ultralow switching barriers along with atomic-scale dipole control—where each intercalated atom acts as an independent,reversible memory bit.Importantly,the polarization magnitude scales linearly with the electrostatic potential difference across the bilayer,providing a quantitative and tunable design rule.Our findings establish a universal and material-agnostic framework for realizing low-power,ultrahighdensity 2D ferroelectric devices on otherwise nonpolar platforms.
