Layered Electrostatic Heterostructures for Electronics and Photonics

非技术描述：当一种材料的尺寸缩小到原子尺寸时，材料的性质就会发生深刻的变化，发现有用现象的新机会就会出现。一个重要的例子发生在二维材料中，这种材料是只有几个原子厚的片状物体。该项目解决了理解这些材料在相互堆叠以构建多层复合材料时的行为的基本挑战。该项目合成的材料在信息技术和能量转换与储存方面具有重要的应用价值。这个项目的研究融入了外展和教育的许多方面。参与该项目的学生将面临材料合成和表征方面的高级挑战。该项目还通过一些活动吸引了更广泛的公众，包括通过展示使用石墨、粘土和云母等艺术用品（所有这些都是由二维材料制成的）来吸引学生参与科学探究。技术描述：最近对石墨烯、氮化硼和二硫化物的片状叠层的涌现特性的观察，被称为范德华异质结构，由于其卓越的电子、光学、化学和机械特性，引起了极大的兴趣。所有研究的范德华异质结构主要是通过弱范德华相互作用结合在一起的，这突出了设计和理解由更强的力（尤其是静电力）结合在一起的多层材料的机会。主要的研究目标是建立模型异质结构，并了解其结构与电子和光子特性之间的关系。该项目结合了实验和理论方法，包括微光谱学来评估光学性质，电导率测量来评估电子耦合和电荷转移，光电光谱结合密度泛函理论计算来评估能带结构。最终，了解这些异质结构中的结构-性能关系可以为设计这些新材料的光电性能提供重要的框架。

Non-technical Description: When a material's size is reduced to atomic dimensions, material properties become profoundly altered, and new opportunities emerge for discovering useful phenomena. An important example of this occurs in two dimensional materials, which are sheet-like objects that are just a few atoms thick. This project addresses fundamental challenges in understanding the behavior of these materials when the two dimensional materials are stacked on top of each other to build a multi-layered composite. The materials synthesized in this project are useful for information technology and energy conversion and storage. The research in this project is integrated into many aspects of outreach and education. The students who work on this project are exposed to advanced challenges in materials synthesis and characterization. This project also engages the broader public through several activities, including outreach to high-school students through demonstrations that use art supplies such as graphite, clay, and mica - all of which are built from two dimensional materials - to engage students in scientific inquiry.Technical Description: Recent observations of emergent properties in few-flake stacks of graphene, boron nitride, and dichalcogenides, termed van der Waals heterostructures, have generated immense interest because of their remarkable electronic, optical, chemical, and mechanical properties. All of the studied van der Waals heterostructures are held together primarily by weak van der Waals interactions, highlighting an opportunity to design and understand multilayered materials that are held together by stronger forces, especially electrostatic forces. The primary research goal is to build model heterostructures and understand the principles that relate their structure to their electronic and photonic properties. This project combines experimental and theoretical approaches, including microspectroscopy to assess the optical properties, conductivity measurements to assess electronic coupling and charge transfer, and photoemission spectroscopy coupled with density functional theory calculations to assess band structure. Ultimately, an understanding of the structure-property relationships in these heterostructures can provide an important framework for designing the optoelectronic properties of these new materials.