Problems associated with large-scale growth of high-quality single-layer bismuthene constitute one of the main obstacles to the applications of bismuthene in electronic devices. Here we report the direct synthesis of high-quality bismuthene using molecular-beam epitaxy on dielectric copper oxide thin films. Scanning tunneling microscopy (STM) reveals the generation of dimer pair arrays and black-phosphorus-like bismuthene (BKP-Bi, α phase) at the initial stage on ${\mathrm{Cu}}_3{\mathrm{O}}_2/\mathrm{Cu}\left(111\right)$ surface. A phase transition from BKP-Bi to blue-phosphorus-like bismuthene (BLP-Bi, β phase) is characterized by high-resolution STM, complemented with first-principles calculations based on density-functional theory (DFT) showing a bond-breaking path. Employing the phase transition, we also demonstrate the construction of an atomically sharp in-plane homojunction along the phase boundary. DFT calculations reveal a one-dimensional edge state along the homojunction.

中文翻译：

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氧化铜上单层铋相变的原子机制

与高质量单层铋的大规模生长相关的问题构成了铋在电子设备中应用的主要障碍之一。在这里，我们报告了在介电氧化铜薄膜上使用分子束外延直接合成高质量铋。扫描隧道显微镜 (STM) 揭示了在初始阶段二聚体对阵列和黑磷状铋 (BKP-Bi, α相) 的产生${铜}_3{\mathrm{哦}}_2/铜\left(111\right)$表面。从 BKP-Bi 到类蓝磷铋（BLP-Bi，β相）的相变以高分辨率 STM 为特征，辅以基于密度泛函理论 (DFT) 的第一性原理计算，显示键断裂小路。利用相变，我们还展示了沿相界构造原子级锐利的面内同质结。DFT 计算揭示了沿同质结的一维边缘状态。