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

技术支持：本项目主要研究大面积、均匀、高质量的二维货车瓦磊晶异质结构的合成。2D异质结构由外延堆叠在一起的不同过渡金属二硫属化物材料（TMDC）的多个单层组成。与其他合成2D TMDC材料的方法不同，该项目探索了主要研究者开发的独特的自限制化学气相沉积工艺。该项目涉及协同努力，在控制可扩展的合成的2D TMDC异质结构的发展，并在异质结构的物理特征和能带结构之间的相关性的理解。它从自限性生长机制的基本原理的研究开始，然后基于基本理解开发控制可扩展合成的技术。它还涉及基于拉曼的表征计量工具的开发，以提供异质结构的组成和结构的高通量表征。此外，首席研究员计划检查异质结构的能带结构和物理特征之间的相关性。 非技术性：该项目解决了材料科学新兴前沿领域的基本挑战。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，其成分和结构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，该目标旨在研究2D异质结构的新物理现象，并探索这些材料在光电子领域的应用。新材料平台可以为信息技术、太阳能收集、发光二极管和柔性电子/光子器件等广泛领域开辟未开发的机会。该项目的研究部分被整合到多方面的教育和推广活动中，旨在激励学生（高中，本科和研究生）追求STEM学科的职业生涯，并旨在加强材料科学的中学和大学课程。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预科科学竞赛和高中AP化学课的客座讲座。

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.