Spatially Tunable Interfacial Ferroelectricity in Low-Symmetric WTe<sub>2</sub>.

Chiang, Yi-Cheng; Chen, Chun-An; Lin, Che-Min; Lin, Erh-Chen; Zhu, Hong-Sen; Liu, Po-Yen; Lin, Yu-Ting; Fan, Sheng-Hung et al. · Nano Lett · 2026

basic_science · Level V

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Abstract

Interfacial ferroelectricity, recently discovered in van der Waals (vdW) materials, exhibits switchable dipoles at the interface. Most experiments are realized by stacking high-symmetry two-dimensional (2D) lattices in specific stacking configurations. A prototype based on a synthetic and low-symmetry 2D lattice is robust for switchable dipoles with broken symmetry at the interface. Here, we show that interfacial ferroelectricity can be spatially tunable by controlling the odd-even layer number in the synthetic low-symmetry lattice of 1T'-WTe<sub>2</sub>. A high ferroelectric transition temperature (<i>T</i><sub>C</sub>) of >550 K is confirmed. The density functional theory (DFT) calculations indicate that interlayer sliding along the <i>b</i>-axis enables polarization switching of the interfacial dipoles. This study moves a significant step toward spatially tunable interfacial ferroelectricity.