Han Ziyi, Wu Shengqiang, Huang Chun, Xuan Fengyuan, Han Xiaocang, Long Yinfeng, Zhang Qing, Li Junxian, Meng Yuan, Wang Lin, Zhou Jiahuan, Hu Wenping, Qiao Jingsi, Geng Dechao, Zhao Xiaoxu
School of Materials Science and Engineering, Peking University, Beijing, 100871, China.
Key Laboratory of Organic Integrated Circuits, Ministry of Education & Tianjin Key Laboratory of Molecular Optoelectronic Sciences, Department of Chemistry, School of Science, Tianjin University, Tianjin, 300072, China.
Nat Commun. 2024 Dec 30;15(1):10835. doi: 10.1038/s41467-024-55130-z.
Crystal symmetry, which governs the local atomic coordination and bonding environment, is one of the paramount constituents that intrinsically dictate materials' functionalities. However, engineering crystal symmetry is not straightforward due to the isotropically strong covalent/ionic bonds in crystals. Layered two-dimensional materials offer an ideal platform for crystal engineering because of the ease of interlayer symmetry operations. However, controlling the crystal symmetry remains challenging due to the ease of gliding perpendicular to the Z direction. Herein, we proposed a substrate-guided growth mechanism to atomically fabricate AB'-stacked SnSe superlattices, containing alternating SnSe slabs with periodic interlayer mirror and gliding symmetry operations, by chemical vapor deposition. Some higher-order phases such as 6 R, 12 R, and 18 C can be accessed, exhibiting modulated nonlinear optical responses suggested by first-principle calculations. Charge transfer from mica substrates stabilizes the high-order SnSe phases. Our approach shows a promising strategy for realizing topological phases via stackingtronics.
晶体对称性决定了局部原子配位和键合环境，是本质上决定材料功能的最重要因素之一。然而，由于晶体中各向同性的强共价/离子键，设计晶体对称性并非易事。层状二维材料因其易于进行层间对称操作，为晶体工程提供了一个理想平台。然而，由于易于沿垂直于Z方向滑动，控制晶体对称性仍然具有挑战性。在此，我们提出了一种衬底引导生长机制，通过化学气相沉积原子级制备AB'-堆叠的SnSe超晶格，该超晶格包含具有周期性层间镜面对称和滑动对称操作的交替SnSe板。可以获得一些高阶相，如6R、12R和18C，第一性原理计算表明它们表现出调制的非线性光学响应。来自云母衬底的电荷转移稳定了高阶SnSe相。我们的方法为通过堆叠电子学实现拓扑相展示了一种有前景的策略。
