EAGER: Transfer by Contact using Adhesion Engineering for Integration of Two-Dimensional Materials into Functional Devices

石墨烯的发现导致了原子薄的二维材料的发现，这些材料具有各种独特的性质。二维材料已经迅速成长为下一代电子、光电子和量子器件的领先材料平台之一。为了将这些材料集成到功能器件中，它们需要从生长衬底中分离出来，并在没有损坏和污染的情况下转移到目标表面。通过目前的转移技术实现这种材料集成是具有挑战性的，目前的转移技术通常依赖于使用额外支撑层的湿法和高温工艺。这一早期概念探索性研究补助金(AGIRE)项目旨在通过开发和了解一种干燥和低温工艺来克服这些挑战，该工艺允许通过单一的直接接触和分层步骤将二维材料直接从源转移到目标，而不需要支撑层。这样的技术可以帮助减少转移过程中的损害和污染，以实现以可扩展和高吞吐量的方式实现否则难以实现的结构。因此，这个转移平台可以帮助提升我国在快速发展的二维材料及其应用领域的全球竞争力。这项研究计划将为学生提供在这一领域进行培训的机会。这项研究的结果将直接整合为正在开发的一门新课程的实验室教学模块。本研究的目的是开发一种干燥、低温、无牺牲层的单层二维转移材料。在这种方法中，当使用对准的转印平台在受控条件下使源表面和目标表面接触并分层时，转印发生。实现这一点的基础是设计目标衬底表面，使其相互作用和附着机制超越范德华力，从而促进成功转移。EIGER将开发这一2D单层转移的方法，通过调整表面化学终止和机械特性、研究粘合机制、探测转移质量并相应地优化转移质量，从而将重点放在表面粘合工程上。该奖项反映了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。

The discovery of graphene has led to the discovery of atomically thin two-dimensional materials with diverse and unique properties. Two-dimensional materials have rapidly grown into one of the leading material platforms for next-generation electronics, optoelectronics and quantum devices. For these materials to be integrated into functional devices, they need to be isolated from their growth substrate and transferred onto a target surface without damage and contamination. This materials integration is challenging to achieve through the current transfer techniques which generally rely on wet and high temperature processes using additional support layers. This EArly-concept Grant for Exploratory Research (EAGER) project looks to overcome these challenges by developing and understanding a dry and low-temperature process that allows direct transfer of two-dimensional materials from a source to target by a single direct contact and delamination step without a need for a support layer. Such a technique can help reduce damage and contamination during the transfer to achieve otherwise hard to realize structures in a scalable and high-throughput manner. As a result, this transfer platform can help in promoting our nation’s global competitiveness in the rapidly evolving field of two-dimensional materials and their applications. This research program will provide opportunities for training students in this area. The results of this research will be directly integrated as a laboratory teaching module in a new course being developed. The aim of this research is to develop a dry, low-temperature, sacrificial layer-free transfer of monolayer two-dimensional materials. In this approach, transfer occurs as the source and target surfaces are brought into contact and delaminated under controlled conditions using an aligned transfer printing platform. Foundational to this is engineering of the target substrate surface with interactions and adhesion mechanisms beyond van der Waals forces that promote a successful transfer. This EAGER will develop this approach for 2D monolayer transfer with a focus on surface adhesion engineering through tuning the surface chemical terminations and mechanical characteristics, studying the adhesion mechanisms, probing the transfer quality and accordingly optimizing for a damage and contamination-free transfer.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.