Collaborative Research: Wafer-Scale Nanomanufacturing of 2D Atomic Layer Material Heterostructures Through Exfoliation and Transfer

二维原子层材料是半导体和能源器件技术的强有力的候选材料。当堆叠在一起时，形成三维异质纳米结构。由于二维材料之间的弱垂直相互作用，它们的异质结构显示出独特的器件功能和新颖的物理现象。然而，由于缺乏控制层数的方法和有限的制造规模，制造这种二维构建块和三维异质结构是非常具有挑战性的。该奖项支持建模和实验研究，以开发通过剥离和转移的晶片级二维材料异质结构的低成本纳米制造工艺。该技术提供了独特的功能，能够制备各种各样的独立单层二维材料，并提供了在晶圆级异质集成的潜力。该项目的成功广泛影响了高性能、原子薄的半导体器件技术，如新型晶体管、太阳能电池、发光二极管（LED）、光电探测器、激光器和传感器，这些技术可以触及日常生活的方方面面。因此，这项研究的结果对美国经济和社会都有好处。该项目更广泛的影响计划包括通过密集的纳米工程实验室模块学习将教科书理论应用于工业应用，其中包括剥离和转移过程的结果，以制造2D材料的异质结构。所提出的层分辨分裂（LRS）工艺通过精确控制各种各样的二维（2D）材料的剥离和转移来实现晶片级非均匀集成的2D原子层构建块的制造。该研究小组证明了LRS技术的可行性，通过在晶片上执行多层2D材料的“一次生长”来在晶片规模上制造多层单层材料。此外，所提出的干堆叠工艺与通过湿堆叠制备的异质结构相比显著提高了晶片级异质结构的性能。最终，该项目通过提供一个可靠的平台来制造单层分辨晶片级3D异质结构，从而为2D材料研究开辟了新的机会。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Two-dimensional atomic layer materials are strong candidate materials for semiconductor and energy device technologies. When stacked together three-dimensional heterogeneous nanostructures are formed. Owing to weak vertical interaction between two-dimensional materials, their heterostructures display unique device functionality and novel physical phenomena. However, it has been extremely challenging to fabricate such two-dimensional building blocks and three-dimensional heterostructures from them due to a lack of methodology to control layer numbers and limited manufacturing scale. This award supports both modeling and experimental research to develop a low-cost nanomanufacturing process of wafer-scale two-dimensional materials-based heterostructures through exfoliation and transfer. This technology offers unique features of enabling preparation of a wide range of freestanding monolayer two-dimensional materials and providing the potential for heterogeneous integration at wafer-scale. The success of this project broadly impacts high performance, atomically-thin semiconductor device technologies, such as new transistors, solar cells, light emitting diodes (LEDs), photodetectors, lasers, and sensors that could touch every aspect of daily life. Therefore, results from this research benefits both the U.S. economy and society. The project's broader impacts plans involve learning to apply textbook theories to industrial applications through intensive nano-engineering lab modules, which includes results from the exfoliation and transfer process to fabricate heterostructures of 2D materials. The proposed Layer Resolved Splitting (LRS) process enables manufacturing of wafer-scale heterogeneously integrated two-dimensional (2D) atomic layer building blocks by precisely controlling the exfoliation and transfer of a wide variety of 2D materials. The research team demonstrates the feasibility of the LRS technique to manufacture multiple monolayer materials at wafer-scale by performing "one growth" of multiple layers of 2D materials on the wafer. Furthermore, the proposed dry stacking process substantially improves the performance of wafer-scale heterostructures compared to heterostructures prepared by wet stacking. Eventually, this project opens up new opportunities in 2D materials research by providing a reliable platform to manufacture monolayer-resolved wafer-scale 3D heterostructures.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.