Effects of atomic defects at lateral and vertical metal-semiconductor interfaces on the properties of the two-dimensional transition metal dichalcogenide heterostructures

基于过渡金属二硫属化合物（TMDs）的二维异质结构在未来电子和光学器件中的应用是不可能的，除非对金属和半导体异质结构界面处的物理现象有一个完整的了解。我们将研究两种材料相邻生长产生的横向异质结构中的选定二维TMD金属-半导体界面，以及单层金属TMD置于单层半导体TMD顶部的垂直配置。由于在实际器件中经常会出现杂质、掺杂和空位等原子缺陷，本课题的目的是研究这些缺陷对横向和垂直异质界面结构和电学性质的影响。我们使用CVD生长的横向TMD异质结构，我们提供的合作伙伴，我们准备的纵向TMD异质结构的压制和冲压技术。界面的原子结构将用低电压高分辨透射电镜进行球差和色差校正，等离子体激元、激子和芯态将用电子能量损失谱进行研究。实验结果将合理化，通过第一性原理计算，我们希望从中获得深入了解的界面缺陷的作用的二维异质结构的性能。

The applications of two-dimensional (2D) heterostructures based on transition metal dichalcogeni-des (TMDs) in future electronic and optical devices is hardly possible without a complete under-standing of the physical phenomena occurring at the interfaces in metallic and semiconducting heterostructures. We will study selected 2D TMD metallic-semiconducting interfaces in lateral het-erostructures produced by growth of two materials next to each other, and in the vertical configu-ration with a single-layer metallic TMD placed on top of a single-layer semiconducting TMD. As at-omistic defects such as contaminations, dopants, and vacancies will be always present in practical devices, the aim of this project is to study the influence of these defects on the structure and on the electronic properties of the lateral and vertical heterointerfaces. We use CVD–grown lateral TMD-heterostructures as provided by cooperation partners and we prepare the vertical TMD hetero-structures by sandwiching and stamping techniques. The atomic structure of the interfaces will be investigated by low-voltage high-resolution TEM with spherical and chromatic aberration correc-tion, and the plasmon, excitons and core states will be studied by electron energy-loss spectrosco-py. The experimental findings will be rationalized through first-principles calculations from which we expect to gain in-depth understanding of the role of interfacial defects on the properties of the 2D heterostructures.