CAREER: Atomic Scale Design of van der Waals Heterostructure Nanoribbons

非技术描述：组合二维（2D）层状材料，例如石墨烯（碳的一个原子层）和过渡金属二硫属化物，以形成异质结构，提供了按需调节材料的电子和光子性质的创新途径。除了近年来已经实现的原子层的垂直堆叠之外，新型2D材料还可以通过生产准一维条带（称为纳米带）来实现。该CAREER奖的研究部分侧重于理解合成一类新材料背后的基础科学，这些材料只有一个原子厚，宽度可控，可达纳米尺度：货车德瓦尔斯异质结构纳米带（vdW带）。这些vdW带可以表现出随着带边缘的宽度和终止而变化的能带隙、铁磁性和半金属性质。首席研究员正在利用先前的研究经验和学术界，工业界和政府的广泛合作来开发基础理论，合成技术和设备架构，以建立vdW带作为材料科学的新范式。重要的是，该项目为研究生和本科生提供了学术界以外的研究和工程准备，为工业实习提供了机会，并开发了新的研讨会，将这些原子厚材料的科学与公众联系起来。技术描述：过渡金属二硫属化物的二维异质结构的预测特性表明，这些材料具有强大的潜力，可以影响下一代光电子学。原子层的异质堆叠，同时在纳米尺度上控制它们的垂直和横向尺寸，将显著增强对这些新型材料系统的电子、光子和磁性的控制。更具体地说，CAREER奖的目标是：1）开发预测VDW异质结构纳米带的光电和输运性质的理论模型; 2）建立能够以原子精度逐层合成的新型金属有机化学气相沉积工艺; 3）证明层堆叠对VDW固体中纳米级相互作用和性质的影响; 4）对边缘终止和缺陷形成对vdW异质带光电性能的影响有了基本的认识。

Non-technical Description: Combining two-dimensional (2D) layered materials, such as graphene (one atomic layer of carbon) and transition metal dichalcogenides, to form heterostructures provides innovative routes of tuning electronic and photonic properties of materials on-demand. In addition to vertical stacking of atomic layers, which has been achieved in recent years, novel 2D materials can also be realized by producing quasi-one-dimensional strips, known as nanoribbons. The research component of this CAREER award focuses on understanding of the fundamental science behind synthesizing a new class of materials that are only one-atom thick, with controllable width down to the nanometer scale: van der Waals heterostructure nanoribbons (vdW ribbons). These vdW ribbons may exhibit energy band gaps, ferromagnetism, and half-metallic properties that vary with width and termination of the ribbon edges. The principal investigator is utilizing prior research experience and broad collaborations across academia, industry, and government to develop the foundational theory, synthesis techniques, and device architectures to establish vdW ribbons as a new paradigm in materials science. Importantly, this project prepares graduate and undergraduate students for research and engineering beyond academia by providing opportunities for industrial internships and developing new workshops for bridging the science of these atom-thick materials to the general public.Technical Description: The predicted properties of two-dimensional heterostructures of transition metal dichalcogenides indicate that these materials have strong potential to impact next-generation optoelectronics. Heterogeneous stacking of the atomic layers while controlling their vertical and lateral dimensions at the nanoscale will significantly enhance the control of the electronic, photonic, and magnetic properties of these novel material systems. More specifically, the objectives of the CAREER award are: 1) Developing theoretical models that predict the optoelectronic and transport properties of vdW heterostructure nanoribbons; 2) Establishing novel metal-organic chemical vapor deposition processes capable of layer-by-layer synthesis with atomic precision; 3) Demonstrating the impact of layer stacking on nanoscale interactions and properties in vdW solids; and 4) Developing fundamental understanding of the roles of edge termination and defect formation on the optoelectronic properties of vdW hetero-ribbons.