Tailoring electronic and photonic properties of van der Waals semiconductor heterostructures

非技术描述：在纳米级量身定做材料的能力一直是许多技术突破的关键推动因素，用于计算和信息技术的半导体的持续发展就是例证。在过去的几年里，出现了一种新的电子材料--厚度只有一个或几个原子的原子晶体，被称为二维材料。这些材料体系为电子和光子器件提供了一个新的平台。研究这些材料性质的一个有趣的方法是将不同类型的材料堆叠起来，形成新的杂化层状材料。所得到的堆叠的电子性质受各层之间的电动力和相互作用的控制。本研究探讨了决定层间相互作用的控制因素。这项研究的结果被用来实现具有理想的电学和光学性能的堆栈的合理设计，这可能适用于新型光电子器件。在教育方面，设计了一个专门的课程工作，向研究生和本科生介绍材料研究的这一新前沿。此外，以实验室为基础的发现过程旨在通过暑期实习计划接触到高中生。技术描述：半导体异质结构的引入使许多新颖的电子和光子学设计成为可能，导致了半导体技术的变革。最近原子薄晶二维(2D)半导体的出现为将半导体异质结推向新的前沿创造了令人兴奋的新机会。特别是，垂直堆积的范德华(VDW)异质结很快被认为是制造原子薄异质结的强大平台，具有极大的设计灵活性。一个核心的科学问题是层间耦合的作用，它可以单独改变每个VDW层的电子结构，以及整个堆栈的电子结构。本项目系统地研究了层间原子排列对VDW异质结电子结构的影响。此外，使用层间耦合作为设计参数，本研究创造了一系列具有新颖的电子和光子性质的2D电子超晶格。从科学上讲，这些活动为该领域的研究人员提供了重要的设计参数，以定制VDW异质结构的电子和光子结构。在技术上，由这一新的研究路线驱动的新一代电子和光子材料和器件具有造福社会的重要应用。在教育方面，通过这项研究培养的研究生获得了广阔的科学视角。通过开设特别课程，国际纳米学院继续加强全校的纳米科学和纳米技术研究生/本科生教育。这项研究还使来自代表性不足群体的学生能够更广泛地参与进来。这一奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Nontechnical description: The ability to tailor materials at the nanoscale has been a key enabler for many technology breakthroughs, exemplified by the continuing development of semiconductors for computing and information technologies. Over the last few years, a new class of electronic materials has emerged - atomic crystals with a thicknesses of only one or a few atoms, known as two-dimensional materials. These materials systems provide a new platform for electronic and photonic devices. One interesting approach to investigating the nature of these materials is by stacking various types of them to form new hybrid layered materials. The electronic properties of the resulting stacks are governed by electrical forces and interactions between the various layers. This research explores the controlling factors that determine the interlayer interactions. Findings from this study are used to achieve rational design of stacks with desirable electronic and optical properties, which may be suitable for new types of optoelectronic devices. Educationally, a special topic course work is designed to introduce this new frontier of materials research to graduate and undergraduate students. In addition, a laboratory-based discovery process is designed to reach out to high school students through a summer internship program.Technical description: The introduction of semiconductor heterostructures enabled many novel designs of electronics and photonics, leading to transformative semiconductor technologies. The recent emergence of atomically thin crystalline two-dimensional (2D) semiconductors creates exciting new opportunities for pushing semiconductor heterostructures towards a new frontier. In particular, vertically stacked van der Waals (vdW) heterostructures were quickly recognized as a powerful platform for creating atomically thin heterostructures with great design flexibility. A central scientific issue is the role of interlayer coupling, which can alter the electronic structures of each vdW layer individually, and the stack as a whole. This project systematically investigates how interlayer atomic alignment impacts the electronic structure of vdW heterostructures. Moreover, using interlayer coupling as the design parameter, the research creates a sequence of 2D electronic superlattices with novel electronic and photonic properties. Scientifically, activities provide researchers in the field with important design parameters to tailor the electronic and photonic structures of vdW heterostructures. Technologically, the new generation of electronic and photonic materials and devices driven by this new line of research have important applications that benefit society. Educationally, graduate students trained through this study gain a broad scientific perspective. Through the design of a special course, the PI continues to enhance campus-wide graduate/undergraduate education in nanoscience and nanotechnology. The research also enables broadening participation of students from underrepresented groups.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.