Ferroelectric Properties of Two-Dimensional Materials

Ferroelectricity in two-dimensional (2D) materials arises when a layer or heterostructure exhibits a spontaneous electric polarization that can be reversed by an external field. Advances in crystal synthesis and nanoscale characterisation have revealed multiple mechanisms of polar ordering in van der Waals sheets, including conventional ion‐displacement, charge‐transfer in single‐element layers and twist‐ or slide‐induced interfacial dipoles. Such 2D ferroelectrics combine high remnant polarisation with mechanical flexibility, atomically sharp domain walls and compatibility with heterogeneous integration. Room-temperature stability down to the monolayer limit, tunable in-plane and out-of-plane orientations, and emergent sliding phenomena open avenues for ultra-compact memory, neuromorphic computing and adaptive optoelectronics.

Research from Nature Portfolio

Studies of a black phosphorus-like bismuth monolayer have demonstrated single-element ferroelectricity, where buckled sp-orbital hybridisation breaks inversion symmetry and produces a robust in-plane polarisation. Scanning probe microscopy visualises reversible switching and reveals anomalous potential profiles at 180° tail-to-tail domain walls.

Twisted heterostructures of monolayer MoS₂ show interfacial ferroelectric domains controlled by the twist angle. Broken inversion symmetry at the interface produces out-of-plane dipoles arranged into a twist-tunable network, enabling field-driven domain-wall motion and proof-of-principle ferroelectric transistor operation.

Yttrium-doped γ-InSe flakes exhibit both out-of-plane and in-plane switchable polarisation at room temperature. Microstructural modifications eliminate stacking faults, enhance pre-sliding displacements and yield a large piezoelectric constant, broadening the family of intrinsic 2D ferroelectrics for nanoelectronic applications.

Ferroelectric Properties of Two-Dimensional Materials publication trend

The graph below shows the total number of articles in ferroelectric properties of two-dimensional materials across all publications each year (not limited to Nature Index journals).

Technical terms

Ferroelectricity: The property of a material to maintain a spontaneous electric polarisation that can be reversed by an applied external electric field.

Van der Waals materials: Layered crystals bound by weak van der Waals forces, allowing exfoliation to atomic thickness while preserving in‐plane bonding.

Inversion symmetry: A spatial symmetry in which a structure is unchanged when all coordinates are inverted; its breaking is essential for polar order.

Sliding ferroelectricity: A mechanism whereby relative lateral displacement of adjacent layers in a non-centrosymmetric stack induces reversible interfacial dipoles.

Domain wall: A nanoscale boundary between regions of different polarisation orientation, which can be moved by external fields and governs switching dynamics.

References

1. Two-dimensional ferroelectricity in a single-element bismuth monolayer. Nature (2023).
2. Interfacial ferroelectricity in marginally twisted 2D semiconductors. Nature Nanotechnology (2022).
3. Orthogonal Electric Control of the Out‐Of‐Plane Field‐Effect in 2D Ferroelectric α‐In2Se3. Advanced Electronic Materials (2020).
4. Ultrafast Electrochemical Synthesis of Defect‐Free In2Se3 Flakes for Large‐Area Optoelectronics. Advanced Materials (2020).