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，发现有用的现象的新机会就会出现。一个重要的例子出现在二维材料中，这种材料是薄片状的物体，只有几个原子厚。这个项目解决了当二维材料堆叠在一起形成多层复合材料时，理解这些材料的行为的根本挑战。该项目所合成的材料可用于信息技术和能量转换与储存。该项目的研究纳入了外联和教育的许多方面。从事这一项目的学生将面临材料合成和表征方面的高级挑战。该项目还通过几项活动吸引了更广泛的公众，包括通过演示高中生使用石墨、粘土和云母等艺术用品-所有这些都是由二维材料制成-来吸引学生进行科学研究。技术描述：最近对石墨烯、氮化硼和二碳化合物(称为范德瓦尔斯异质结构)的稀薄堆叠中的新特性的观察引起了极大的兴趣，因为它们具有显著的电子、光学、化学和机械性能。所有研究的范德华异质结构主要通过弱的范德华相互作用保持在一起，这突出了设计和理解通过更强的力，特别是静电力保持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，并了解其结构与其电子和光子性质之间的关系的原理。这个项目结合了实验和理论的方法，包括用来评估光学性质的显微光谱学，用来评估电子耦合和电荷转移的电导率测量，以及用光电子能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-性质关系可以为设计这些新材料的光电性质提供一个重要的框架。

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.