Spatially Tunable Interfacial Ferroelectricity in Low-Symmetric WTe₂

Area of Science:

• Condensed Matter Physics
• Materials Science
• Nanotechnology

Background:

• Interfacial ferroelectricity in van der Waals (vdW) materials involves switchable dipoles at interfaces.
• Current research often relies on stacking high-symmetry 2D lattices.
• Low-symmetry 2D lattices offer a robust platform for interfacial ferroelectricity due to inherent broken symmetry.

Purpose of the Study:

• To demonstrate spatially tunable interfacial ferroelectricity.
• To investigate the role of layer number in synthetic low-symmetry lattices.
• To explore the potential of 1T -WTe2 for tunable ferroelectric properties.

Main Methods:

• Fabrication of synthetic low-symmetry 1T -WTe2 lattices with controlled odd-even layer numbers.
• Experimental characterization of ferroelectric properties and transition temperatures.
• Density Functional Theory (DFT) calculations to elucidate polarization switching mechanisms.

Main Results:

• Demonstrated spatial tunability of interfacial ferroelectricity by controlling the odd-even layer number in 1T -WTe2.
• Confirmed a high ferroelectric transition temperature (Tc) exceeding 550 K.
• DFT calculations revealed that interlayer sliding along the b-axis facilitates polarization switching.

Conclusions:

• Interfacial ferroelectricity in 1T -WTe2 is spatially tunable via layer number control.
• The material exhibits a high ferroelectric transition temperature, suitable for practical applications.
• This work represents a significant advancement towards controllable interfacial ferroelectricity in van der Waals heterostructures.