Binary two-dimensional (2D) materials comprising main group elements with several phases of AB and AB₂ stoichiometry provide significantly rich physics and application potentials. We present the epitaxial growth of two phases of atomically thin SnSb on a Cu₂Sb surface alloy under ultrahigh-vacuum (UHV) conditions. Theoretical studies predict that these 2D SnSb sheets adopt the atomic configurations similar to those of black and blue phosphorene but with Sb–Sn–Sn–Sb motif (R- and H-phases) holding an indirect band gap of 0.20 and 0.85 eV, respectively. Our low-temperature (77 K) scanning tunneling microscopy characterizations, and first-principles theoretical calculations, reveal the atomic structures and semiconducting properties of the most stable H-phase, displaying a commensurate lattice growth mode on Cu₂Sb(111) but a weak interfacial interaction. Strain-engineered band gap, effective mass, and Young’s Modulus of the most stable H-phase are further explored theoretically. These results suggest that 2D SnSb with intriguing properties has great potential for electronics in an atomically thin platform.

中文翻译：

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二维SnSb二元蜂窝晶格的实验实现和相位工程

包含具有AB和AB ₂化学计量学数相的主族元素的二元二维(2D)材料提供了非常丰富的物理和应用潜力。我们展示了两相原子级薄 SnSb 在 Cu ₂上的外延生长超高真空 (UHV) 条件下的 Sb 表面合金。理论研究预测，这些 2D SnSb 片采用类似于黑色和蓝色磷烯的原子构型，但 Sb-Sn-Sn-Sb 基序（R 相和 H 相）的间接带隙分别为 0.20 和 0.85 eV . 我们的低温 (77 K) 扫描隧道显微镜表征和第一性原理理论计算揭示了最稳定的 H 相的原子结构和半导体特性，在 Cu ₂上显示出相应的晶格生长模式Sb(111) 但界面相互作用较弱。从理论上进一步探讨了最稳定 H 相的应变工程带隙、有效质量和杨氏模量。这些结果表明，具有有趣特性的 2D SnSb 在原子级薄平台中具有巨大的电子学潜力。