二维材料同质和异质结构层间电学输运特性与层间转角关系的实验研究

Interlayer electrical transport of homo- and hetero- structures of two-dimensional (2D) materials strongly depends on their rotational misalignment angle. The study on the relationship between interlayer electrical transport of homo- and hetero- structures of 2D materials and their rotational misalignment angle is of great significance for controlling their physical properties and their applications in nanoelectronic and opto-electronic devices. However, in contrast with extensive studies in theory, there are very few experimental studies on the topic due to the great challenges. Herein, we plan to develop new experimental methods for studying the relationship between interlayer electrical transport of homo- and hetero- structures of 2D materials and their rotational misalignment angle based on in-situ scanning electron microscope, apply the methods to typical homo-structures (graphene-graphene, MoS2-MoS2) and hetero-structures (graphene-MoS2, MoS2-WSe2 and graphene-boronitrene-graphene) of 2D materials. Our study aims to give new insights into the interlayer electrical coupling and interlayer electrical transport of homo- and hetero- structures of 2D materials, and provide new methods for controlling their interlayer electrical transport.

二维材料同质和异质结构的层间电学输运特性与层间转角具有较强的依赖关系，研究该相互关系对于调控二维材料同质和异质结构的物理性质及其在纳米电子和光电子器件中的应用均具有重要的意义，但是由于实验难度大、现有实验方法不能很好地满足实验研究的需求，其实验研究远滞后于理论研究。本项目拟基于原位扫描电子显微镜发展可研究二维材料同质和异质结构层间电学输运特性与其层间转角关系的实验新方法，并利用该方法研究典型二维材料同质结构（包括石墨烯-石墨烯、MoS2-MoS2）和异质结构（包括石墨烯-MoS2、MoS2-WSe2和石墨烯-硼氮烯-石墨烯）的层间电学输运特性与其层间转角的连续和全角程变化关系，拟解决两个关键科学问题：（1）二维材料同质和异质结构的层间电学耦合和输运规律，和（2）二维材料同质和异质结构层间电学输运特性的调控方法。

二维材料层间通过范德华相互作用结合，其层间的力学和电学特性以其与层间耦合强度（可通过层间转角调控）的相互关系对于二维材料的应用具有重要的意义。本项目围绕二维材料层间的电学和力学特性开展研究，基于微加工的二维材料小岛结构和原位扫描电子显微镜中纳米探针操纵发展了原位构建二维材料同质和异质结构的新方法，揭示了石墨烯同质结构层间电学输运与层间转角的关系；发展了测量二维材料层间结合能和同时测量二维材料弹性和黏性的实验新方法，实现石墨烯、MoS2二维材料的层间结合能及其与金衬底黏附能的测量；发展了测量二维材料层间电学输运特性与层间拉压应力关系的实验新方法，揭示石墨烯层间电学输运特性与层间拉压应力的关系。相关成果加深了对二维材料层间电学和力学特性的理解和认识，对于二维材料在纳米电子器件、微机电系统等领域的应用具有重要意义。