Pseudosymmetric Epitaxy for Scalable Growth of Uniform Two-Dimensional Ferroelectric α-In 2 Se 3 Monolayer

作者：Lei Xu, Zhenhua Wu, Yutao Han, Mingzheng Wang, Jiao Li, Chen Chen, Lin Wang, Yakun Yuan, Lei Shi, Joan M. Redwing, Xiaotian Zhang · 发表于：Nano Letters · 年份：2025 · DOI：10.1021/acs.nanolett.5c01935 · 被引用次数：15 · 研究领域：2D Materials and Applications、Ferroelectric and Piezoelectric Materials、Perovskite Materials and Applications

The 2D ferroelectric semiconductor α-In 2 Se 3 offers compelling opportunities for next-generation ultrathin electronics, but the controllable growth of a monolayer with large-scale uniformity and single phase has proven challenging. Here, we demonstrate the pseudosymmetry epitaxial growth of a uniform centimeter-scale α-In 2 Se 3 monolayer by leveraging a fluorophlogopite mica (F-mica) substrate with its pseudohexagonal surface atom configuration, in a confined space chemical vapor deposition setup. Transmission electron microscopy and in-plane XRD reveal the pseudohexagonal symmetry of an F-mica surface and establish the in-plane epitaxial relation of (100) α-In 2 Se 3 ∥(010) F-mica with a 4 × 4 α-In 2 Se 3 unit cell matching the 3 × 3 F-mica surface. Second-harmonic generation and piezoresponse force microscopy confirm the homogeneity and polarization of the films. A ferroelectric semiconductor junction array based on the α-In 2 Se 3 films exhibits consistent and reliable multipattern memorization and an enhanced On/Off ratio over 10 5 . Our strategies offer critical insights into pseudosymmetric epitaxy of 2D materials and pave the way for advanced ultrathin ferroelectric memory technologies.