Du Xiaojia, Lee Yangjin, Zhang Yan, Yu Tianhao, Kim Kwanpyo, Liu Nan
Beijing Key Laboratory of Energy Conversion and Storage Materials, College of Chemistry, Beijing Normal University, Beijing 100875, P. R. China.
Department of Physics, Yonsei University, Seoul 03722, Korea.
ACS Appl Mater Interfaces. 2021 May 19;13(19):22819-22827. doi: 10.1021/acsami.1c03135. Epub 2021 May 4.
Constructing a bilayer system with defined twist angles is an effective way to engineer the physical properties of two-dimensional (2D) materials, opening up a new research area of twistronics. How to achieve high-quality bilayer 2D materials in a controlled and mass production way is of primary importance to this emerging area. In this work, we present a strategy for the large-scale fabrication of twisted bilayer molybdenum disulfide (MoS) through photolithography patterning and folding of single-crystal monolayer MoS. Atomic resolution transmission electron spectroscopy directly confirms that the as-achieved folded bilayer MoS is of high quality with targeted twist angles. Various twist angles result in tuning Raman mode frequencies and direct optical transition energies. Due to the weak interlayer coupling between the twisted layers, folded bilayers exhibit an extremely high photoluminescence with doubled intensity as compared to the unfolded monolayer, indicating a possible application in optoelectronic devices. Our work provides a new strategy to tailor the properties of MoS, which will be beneficial to twistable electronics.
构建具有特定扭转角的双层系统是调控二维（2D）材料物理性质的有效方法，由此开辟了一个新的研究领域——扭曲电子学。如何以可控且大规模生产的方式制备高质量的双层二维材料，对于这个新兴领域至关重要。在这项工作中，我们提出了一种通过光刻图案化和单晶单层二硫化钼（MoS）折叠来大规模制备扭曲双层二硫化钼（MoS₂）的策略。原子分辨率透射电子能谱直接证实，所制备的折叠双层MoS₂具有高质量且扭转角符合目标要求。不同的扭转角会导致拉曼模式频率和直接光学跃迁能量发生调谐。由于扭曲层之间的层间耦合较弱，折叠双层表现出极高的光致发光特性，其强度是未折叠单层的两倍，这表明在光电器件中具有潜在应用价值。我们的工作为调控MoS₂的性质提供了一种新策略，这将有利于可扭曲电子学的发展。
