Electronic structure of transition metal-trihalide based van der Waals heterostructures

由二维材料年构成的异质结在过去的几年里引起了相当大的科学关注。最近，磁性2D材料的发现和扭曲的双层石墨烯的杰出性质的发现进一步推动了这一领域的发展。一些2D材料被认为是克服传统半导体技术物理局限性的潜在候选者，这正成为先进器件制造的瓶颈。本项目的目的是利用光电子能谱研究原子薄的过渡金属卤化物如Cr(Cl，Br，I)3和RuCl3的电子结构以及它们与石墨烯的异质结构。这将导致更好地了解它们的性质以及外部参数影响这些系统的方式。虽然RuCl3是实现量子自旋液体的候选材料，但Cr(Cl，BrI)3将磁性保持到单分子层，是一种很有前途的纳米器件材料。特别是，石墨烯的异质结构是基于2D材料的器件的重要组成部分。带状排列和杂化效应的知识对于彻底理解界面性质是至关重要的。可能会发生跨异质结构的电荷转移和磁交换参数的修改。此外，当掺杂或产生受控缺陷后，异质双薄膜和薄膜的电子结构甚至可能在质量水平上发生变化。

Heterostructures made of 2D material years attracted considerable scientific attention in the last years. Recently the field received an additional boost by the discovery of magnetic 2D materials and of the outstanding properties of twisted bilayer graphene. Some 2D materials are considered potential candidates to overcome physical limitations of conventional semiconductor technology, which is becoming a bottleneck for advanced device manufacturing.The aim of the project is the investigation of the electronic structure of atomically thin transition metal halides such as Cr(Cl,Br,I)3 and RuCl3 and their heterostructures with graphene by means of photoemission spectroscopy. This should lead to a better understanding of their properties and the way external parameters influence these systems. While RuCl3 is a candidate for the realization of a quantum spin liquid, Cr(Cl,Br,I)3 retains magnetism down to the monolayer and is a promising material for nanoscale devices. In particular, heterostructures with graphene are an important building block of devices based on 2D materials. Knowledge of band alignment and hybridization effects is crucial for a thorough understanding of the interface properties. Charge transfer across the heterostructure may occur and modifications of the magnetic exchange parameters. Moreover, the electronic structure of heterobilayers and thin films may change even on a qualitative level when doped or after controlled defect creation.