Synthesis, Properties and Structure-Function Relationships in Ferecrystals: New Compounds Composed of Stacked 2D Layers with Designed Nanoarchitecture

非技术摘要：材料研究中的一个重大挑战是制备具有设计性能的新型化合物。通过复杂的分层方案创建稳定的分层材料的能力提供了前所未有的能力来探索成分的结构、组成和物理性能之间的相互作用。这项研究产生了丰富的新材料集合，具有不同和非常不寻常的性质，并改进了对含有不同结构层的化合物的结构-性质关系的理解。目标是了解物理属性对各个层的身份、厚度和顺序的依赖关系。第二个目标是了解导致制备稳定产品的合成方法的基本方面。当前和未来的技术对国际竞争力至关重要，取决于能否制备和表征稳定的层状材料以获得增强的性能，这是任何单个部件都找不到的。技术摘要：这项研究扩展了一种合成方法，以创造包含两个或更多结构不同的组分的新的层状固体，它们之间具有原子突变的界面。设计的前驱体使具有设计的纳米结构的动力学稳定的异质结构能够在大范围内制备。该项目的目标是了解异质结构中纳米结构对输运性质的依赖，该异质结构包含电隔离的过渡金属二卤化物、硫化物铋和相关的三元结构的二维层。可变厚度的大带隙间隔层电隔离二碳化合物单分子层，并且使用相邻的磁性层来扰乱单分子层。这项研究是及时的，因为最近的发现有望在各种技术方面取得进展，包括隧道晶体管、柔性电子设备、光电探测器、光伏和具有前所未有的特性和/或独特功能的发光设备。这项研究为研究生在沉积技术、薄膜表征技术以及2D异质结构中出现的物理现象方面提供了广泛的技术背景。这种培训使他们能够在高科技行业、学术界或国家实验室的职业生涯中茁壮成长。

Non-technical Abstract:A grand challenge in materials research is the preparation of novel compounds with designed properties. The ability to create stable layered materials with complicated layering schemes provides an unprecedented ability to probe the interplay between structure, composition, and physical properties of the constituents. This research produces a rich collection of new materials with diverse and highly unusual properties and an improved understanding of structure-property relationships in compounds containing structurally different layers. A goal is to understand the dependence of physical properties on the identity, thickness, and the sequence of individual layers. A second goal is to understand the fundamental aspects of the synthesis approach that result in the preparation of stable products. Current and future technologies crucial to international competitiveness depend on being able to both prepare and characterize stable layered materials to obtain enhanced properties, which are not found in any of the individual components. Technical Abstract:This research extends a synthesis approach to create new, layered solids containing two or more structurally different constituents with atomically abrupt interfaces between them. Designed precursors enable kinetically stable heterostructures with designed nanoarchitectures to be prepared over large areas. The project goal is to understand the dependence of transport properties on nanoarchitecture in heterostructures containing electrically isolated two dimensional layers of transition metal dichalcogenides, bismuth chalcogenides and related ternary structures. Large band gap spacer layers of varying thickness electrically isolate the dichalcogenide monolayers and adjacent magnetic layers are used to perturb the monolayers. This research is timely, as recent discoveries promise advances in a variety of technologies including tunnelling transistors, flexible electronics, photodetectors, photovoltaics and light-emitting devices with unprecedented characteristics and/or unique functionalities. This research provides a broad technical background for graduate students in deposition technologies, thin film characterization techniques, and physical phenomena that occur in 2D heterostructures. This training enables them to thrive in careers in high tech industries, academia or national laboratories.