Low energy ion irradiation of 2D-materials

该后续提案中的研究目标是发现和研究离子辐照在支持的2D材料中引起的现象。一方面，我们将完成在第一个项目阶段已经开始的研究，从同时发展的新观点调查主题，补充现有数据集，并通过发表结果来推动和激励进一步的研究。另一方面，我们将在第一个资助期内出现的重大发现和成就的基础上，探索科学新领域。纳米网：由于对2D材料作为膜应用的兴趣日益浓厚，我们将利用独特的基于莫尔的离子束方法来实现这种膜。我们将完善和发展我们在石墨烯和六方氮化硼中的空位簇纳米网的工作，这些空位簇纳米网由Ir（111）或Pt（111）支撑。在基本面上，我们将进行额外的实验，计算和建模，以了解所发现的神奇空位簇大小的形成和产生双峰空位簇大小分布的机制。在实践方面，我们打算在规则性、均匀和可调尺寸方面优化纳米网形成的配方，以及不存在会使作为过滤膜的应用恶化的较大空位岛。此外，我们将建立这些纳米网层的转移，并通过透射电子显微镜对其进行表征。二.过渡金属二硫化物中的相变：随着过渡金属二硫化物单层作为Ir（111）上石墨烯上的准独立层的可用性，研究离子束如何在这些材料中诱导相变成为可能。作为范例，我们将充分表征可逆离子束诱导的晶体到非晶转变的二硫化钼，包括扫描隧道光谱和显微镜，光致发光，以及拉曼光谱。我们将进一步研究如何离子束可以用来诱导在这样的层的其他结构相变。三.高压化学和同位素分离：最后，我们将利用我们的发现，即在GPa压力下，注入的气体被困在Ir（111）上石墨烯或六方氮化硼单层下的气泡中，即使这些层有很大的缺陷。这一发现意味着高压化学的潜力，如果泡罩可以充满反应气体。此外，由于我们发现温度相关的气体保留也取决于气体种类，我们将探索这种效应是否也可用于同位素分离，例如用于氢和氘的分离。

The objective of the research within this follow-up proposal is to discover and investigate ion irradiation induced phenomena in supported 2D-materials. On the one hand, we will complete research that started already in the first project phase by investigating topics from new viewpoints that developed meanwhile, by supplementing existing data sets, as well as through publication of results in order to advance and stimulate further research. On the other hand, we will build on significant findings and achievements that emerged during the first funding period to explore scientific new ground.I. Nanomesh: Driven by the rising interest in application of 2D-materials as membranes, we will exploit the unique moiré-based ion beam approach for the realization of such membranes. We will refine and develop our work on the vacancy cluster nanomeshes in graphene and hexagonal boron nitride supported by Ir(111) or Pt(111). On the fundamental side we will conduct additional experiments, calculations and modelling to understand the formation of the magic vacancy cluster sizes discovered and the mechanism giving rise to a bimodal vacancy cluster size distribution. On the practical side, we intend to optimize the recipes for nanomesh formation in terms of regularity, uniform and tunable size, as well as the absence of larger vacancy islands that would deteriorate an application as filtering membrane. Moreover, we will establish the transfer of these nanomesh layers and characterize them by transmission electron microscopy. II. Phase transitions in transition metal disulfides: With the availability of transition metal disulfide monolayers as quasi-freestanding layers on graphene on Ir(111) it becomes possible to investigate how ion beams can induce phase transitions in these materials. As a paradigm, we will fully characterize the reversible ion beam induced crystalline-to-amorphous transition of MoS2 including scanning tunneling spectroscopy and microscopy, photoluminescence, as well as Raman spectroscopy. We will furthermore investigate how ion beams can be used to induce other structural phase transitions in such layers. III. High pressure chemistry and isotope separation: Finally, we will utilize our finding that implanted gases are trapped in blisters underneath graphene or hexagonal boron nitride monolayers on Ir(111) at GPa pressures, even when these layers are highly defective. This finding implies a potential for high pressure chemistry, if blisters can be filled with reactive gases. Moreover, as we found that the temperature dependent gas retention also depends on the gas species, we will explore whether this effect may also be used for isotope separation, e.g. for the separation of hydrogen and deuterium.