Van der Waals Heteromaterials

范德华异质材料

基本信息

批准号：
1701390
负责人：
Matthias Batzill
金额：
$ 43.47万
依托单位：
University of South Florida
依托单位国家：
美国
项目类别：
Standard Grant
财政年份：
2017
资助国家：
美国
起止时间：
2017-07-01 至 2022-06-30
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=1701390&HistoricalAwards=false
关键词：
Van der Waals Heteromaterials

项目摘要

Nontechnical Description: Layered materials consists of two-dimensional molecular-planes that are stacked on top of each other and held together by only weak forces. Although the interactions between layers are weak, it has been recently shown that they are critical in controlling the properties of these materials. In nature, layered compounds exhibit identical layer composition. In this project, the research team is combining diverse layered materials with atomic layer precision and thus creates artificially layered materials with novel properties. Specifically, the team is gaining insight how interfaces between dissimilar layered materials controls material properties and this has far reaching implications for designing materials at the nanoscale. Better understanding of interlayer interactions enables discovery of novel materials with applications as diverse as superconductivity or solar energy harvesting. The program advocates the increase of minority students in STEM research and is embedded in activities which allows graduate students to gain experience internationally at research facilities in Europe. Technical Description: Quantum confinement and interlayer hybridization in van der Waals materials strongly modify the properties of single layers compared to bulk materials. The research team aims to understand how such weak interlayer interactions modify the properties of artificial van der Waals heterostructures and explores how these modifications can be utilized for designing materials with desirable properties. In this project, van der Waals heterostructures are synthesized by direct growth of layered materials on van der Waals substrates. The variation of their electronic properties due to interlayer interactions are characterized by angle resolved photoemission spectroscopy and scanning tunneling microscopy/spectroscopy. Scanning probe techniques also allow the characterization of artificially grown nanostructures and lateral interfaces. Quantum critical phenomena, such as charge density wave transitions, are anticipated to be sensitively dependent on interlayer interactions and thus the tuning of transition temperatures is being studied in metallic materials. Band gap tuning as a function of layers and/or interfaces with dissimilar materials are being studied in semiconducting materials. Finally, modifications of single layer electronic properties by molecular adsorption, charge transfer doping, or field effect is explored by combining the capabilities of growing single layers with a new nanoprobe transport measurement under ultra-high vacuum conditions.

非技术描述：分层材料由二维分子平面组成，它们彼此堆叠并仅由弱力固定在一起。尽管层之间的相互作用很弱，但最近已证明它们对于控制这些材料的性质至关重要。在自然界中，分层化合物表现出相同的层组成。在这个项目中，研究团队将各种分层的材料与原子层的精度相结合，从而创建具有新颖性能的人为分层的材料。具体而言，该团队正在洞悉不同的分层材料之间如何控制材料属性，这对在纳米级设计材料具有很大的影响。更好地了解层间相互作用，可以发现具有超导性或太阳能收获的新颖材料。该计划主张在STEM研究中增加少数族裔学生，并嵌入到允许研究生在欧洲研究设施中获得国际经验的活动。技术描述：范德华材料中的量子限制和层间杂交与散装材料相比，强烈修改单层的性质。研究小组旨在了解这种弱层间相互作用如何修改人工范德华异质结构的特性，并探讨如何将这些修饰用于设计具有理想特性的材料。在这个项目中，范德华异质结构是通过在范德华基板上直接生长的分层材料来合成的。由于层间相互作用而引起的电子特性的变化以角度分辨的光发射光谱和扫描隧道显微镜/光谱法的特征。扫描探针技术还允许表征人为生长的纳米结构和横向界面。预计量子临界现象（例如电荷密度波转变）将敏感地取决于层间相互作用，因此在金属材料中研究过渡温度的调整。在半导体材料中研究了带有不同材料的层和/或界面的频带隙调谐。最后，通过将生长单层的能力与在超高真空条件下的新纳米螺旋托传输测量相结合来探索单层电子性能，通过分子吸附，电荷转移掺杂或场效应对单层电子性质进行修改。