CAREER: Van der Waals Epitaxial Heterostructures: Beyond 2D Materials

技术：这个职业项目是研究合成大面积、均匀和高质量的具有可控能带结构的二维(2D)范德华外延异质结构。二维异质结由多层不同的过渡金属二卤化物材料(TMDC)外延堆积在一起组成。与其他合成2D TMDC材料的方法不同，该项目探索了首席研究员开发的一种独特的自限化学气相沉积工艺。该项目包括协同努力，开发可控可扩展的2D TMDC异质结构的合成，并了解异质结构的物理特征和能带结构之间的相关性。它从研究自限制生长机制的基本原理开始，然后在基本理解的基础上发展可控可伸缩合成技术。它还包括开发基于拉曼的表征计量工具，以提供对异质结构的组成和结构的高通量表征。此外，首席研究员计划研究异质结构的能带结构和物理特征之间的相关性。非技术性：这个项目解决了材料科学新兴尖端领域的根本挑战。该项目的成功可以提供合理设计一类新的人造材料的能力，这些材料的组成和结构可以在原子尺度上进行调整。它为首席研究员追求他的职业目标奠定了基础，他的目标是研究2D异质结构的新物理现象，并探索这些材料在光电子学领域的应用。新的材料平台可以为包括信息技术、太阳能收集、发光二极管和灵活的电子/光子设备在内的广泛领域开辟未知的机会。该项目的研究部分被纳入多方面的教育和外联活动，旨在激励学生(高中生、本科生和研究生)在STEM学科中追求职业生涯，并旨在加强中学和大学的材料科学课程。除了为本科生和研究生提供研究培训外，该教育计划还包括指导高中生参加大学前的科学比赛，以及在高中AP化学课堂上的客座讲座。

Technical: This CAREER project is to study the synthesis of large-area, uniform, and high-quality two-dimensional (2D) van der Waals epitaxial heterostructures with controlled band structures. The 2D heterostructure consists of multiple monolayers of dissimilar transition metal dichalcogenide materials (TMDC) epitaxially stacked together. Unlike other approaches for the synthesis of 2D TMDC materials, this project explores a unique, self-limiting chemical vapor deposition process that the principal investigator has developed. The project involves synergistic efforts in the development of controlled scalable synthesis of 2D TMDC heterostructures and in the understanding of correlation between the physical features and band structures of the heterostructures. It starts with studies of the fundamentals of the self-limiting growth mechanism, followed by the development of techniques for the controlled scalable synthesis based on the fundamental understanding. It also involves the development of a Raman-based characterization metrology tool to provide high-throughput characterizations for the compositions and structures of the heterostructures. Additionally, the principal investigator plans to examine the correlation between the band structures and physical features of the heterostructures. Non-technical: This project addresses fundamental challenges in an emerging cutting-edge area of materials science. The success of this project can provide capabilities to rationally design a new class of artificial materials with compositions and structures tuned at the atomic scale. It lays down the groundwork for the principal investigator to pursue his career goal that aims to investigate new physical phenomena of 2D heterostructures and to explore these materials for applications in the field of optoelectronics. The new material platform can open up unexplored opportunities for a wide range of fields including information technology, solar energy harvesting, light emission diodes, and flexible electronic/photonic devices. The research component of this project is integrated into multifaceted educational and outreach activities that aim to inspire students (high school, undergraduate, and graduate) to pursue careers in the STEM disciplines and aim to enhance the secondary school and university curricula in materials science. In addition to providing research training for students at both undergraduate and graduate levels, the education plan includes mentoring high-school students to participate in pre-college scientific competitions and guest lectures in high schools' AP chemistry classes.