Guo Zenglong, Wang Lei, Han Mengjiao, Zhao Erding, Zhu Liang, Guo Weiteng, Tan Junyang, Liu Bilu, Chen Xing-Qiu, Lin Junhao
Department of Physics, Shenzhen Institute for Quantum Science and Engineering (SIQSE), Southern University of Science and Technology, Shenzhen 518055, People's Republic of China.
Shenzhen Key Laboratory of Advanced Quantum Functional Materials and Devices, Southern University of Science and Technology, Shenzhen 518055, People's Republic of China.
ACS Nano. 2022 Jul 26;16(7):11268-11277. doi: 10.1021/acsnano.2c04664. Epub 2022 Jul 18.
2H-1T' MoTe van der Waals heterostructures (vdWHs) have promising applications in optoelectronics due to a seamlessly homogeneous semiconductor-metal coupled interface. However, the existing methods to fabricate such vdWHs involved complicated steps that may deteriorate the interfacial coupling and are also lacking precise thickness control capability. Here, a one-step growth method was developed to controllably grow bilayer 2H-1T' MoTe vdWHs in the small growth window overlapped for both phases. Atomic-resolution low-voltage transmission electron microscopy shows the distinct moiré patterns in the bilayer vdWHs, revealing the epitaxial nature of the top 2H phase with the lattice parameters regulated by the underneath 1T' phase. Such epitaxially stacked bilayer vdWHs modulate the interlayer coupling by resonating their vibration modes, as unveiled by the angle-resolved polarized Raman spectroscopy and first-principles calculations.
由于具有无缝均匀的半导体-金属耦合界面，2H-1T'碲化钼范德华异质结构（vdWHs）在光电子学领域具有广阔的应用前景。然而，现有的制备此类vdWHs的方法涉及复杂的步骤，这可能会降低界面耦合，并且还缺乏精确的厚度控制能力。在此，开发了一种一步生长方法，以在两个相重叠的小生长窗口中可控地生长双层2H-1T'碲化钼vdWHs。原子分辨率低电压透射电子显微镜显示了双层vdWHs中独特的莫尔条纹，揭示了顶部2H相的外延性质，其晶格参数由下面的1T'相调节。如角分辨偏振拉曼光谱和第一性原理计算所示，这种外延堆叠的双层vdWHs通过共振其振动模式来调节层间耦合。
