Ma Liang, Zhu Juntong, Li Wei, Huang Rong, Wang Xiangyi, Guo Jun, Choi Jin-Ho, Lou Yanhui, Wang Dan, Zou Guifu
College of Energy, Soochow Institute for Energy and Materials Innovations, and Key Laboratory of Advanced Carbon Materials and Wearable Energy Technologies of Jiangsu Province, Soochow University, Suzhou 215123 China.
Vacuum Interconnected Nanotech Workstation, Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences (CAS), Suzhou 215123 China.
J Am Chem Soc. 2021 Aug 25;143(33):13314-13324. doi: 10.1021/jacs.1c06250. Epub 2021 Aug 10.
Molybdenum ditelluride (MoTe) has attracted ever-growing attention in recent years due to its novel characteristics in spintronics and phase-engineering, and an efficient and convenient method to achieve large-area high-quality film is an essential step toward electronic applications. However, the growth of large-area monolayer MoTe is challenging. Here, for the first time, we achieve the growth of a centimeter-sized monoclinic MoTe monolayer and manifest the mechanism of immobilized precursor particle driven growth. Microscopic characterizations reveal an obvious trend of immobilized precursor particles being consumed by the monolayer and continuing to provide a source for the growth of the monolayer. Time-of-flight secondary ion mass spectrometry verifies the attachment of hydroxide ions on the surface of the MoTe monolayer, thereby realizing the inhibition of crystal growth along the [001] zone axis and the continuous growth of the MoTe monolayer. The first-principles DFT calculations prove the mechanism of immobilized precursor particles and the absorption of hydroxide ions on the MoTe monolayer. The as-grown MoTe monolayer exhibits a surface roughness of 0.19 nm and average conductivity of 1.5 × 10 S/m, which prove the smoothness and uniformity of the MoTe monolayer. Temperature-dependent electrical measurements together with the transfer characteristic curves further demonstrate the typical semimetallic properties of monoclinic MoTe. Our research elaborates the microscopic process of immobilized precursor particles to grow large-area MoTe monolayer and provides a new thinking about the growth of many other two-dimensional materials.
近年来，二碲化钼（MoTe₂）因其在自旋电子学和相工程方面的新颖特性而受到越来越多的关注，实现大面积高质量薄膜的有效且便捷的方法是迈向电子应用的关键一步。然而，大面积单层MoTe₂的生长具有挑战性。在此，我们首次实现了厘米尺寸单斜MoTe₂单层的生长，并揭示了固定前驱体颗粒驱动生长的机制。微观表征显示，固定前驱体颗粒被单层消耗并持续为单层生长提供源的明显趋势。飞行时间二次离子质谱验证了氢氧根离子在MoTe₂单层表面的附着，从而实现了沿[001]晶带轴的晶体生长抑制以及MoTe₂单层的持续生长。第一性原理密度泛函理论（DFT）计算证明了固定前驱体颗粒以及氢氧根离子在MoTe₂单层上吸附的机制。所生长的MoTe₂单层表现出0.19 nm的表面粗糙度和1.5×10⁻⁵ S/m的平均电导率，这证明了MoTe₂单层的光滑性和均匀性。与转移特性曲线相关的温度依赖电学测量进一步证明了单斜MoTe₂典型的半金属特性。我们的研究阐述了固定前驱体颗粒生长大面积MoTe₂单层的微观过程，并为许多其他二维材料的生长提供了新的思路。
