Perfecting Monolayer Graphene by Defect Removal Using Novel Thermo-Mechanical Methods

最近的实验表明，单层碳原子石墨烯具有令人惊讶的高室温电子迁移率。当硅基技术达到基础物理学规定的自然极限时，这种非凡的电子行为很可能使纳米电子学取得突破性进展。然而，石墨烯的质量控制仍然是一个主要的挑战，因为即使是几个原子缺陷也可能显著降低石墨烯器件的性能。研究小组试图通过综合实验和建模努力，开发一种新的热机械方法，通过有效地去除缺陷来完善石墨烯片。特别是，时间加速建模方法将被开发，以确定缺陷迁移障碍和路径以及热和机械载荷下缺陷的反应机制。同时，将在热机械处理前后对悬浮单层石墨烯器件的拉曼形貌、电输运和低温磁输运进行实验测量，旨在验证建模方法并评估方法的有效性。为完善石墨烯片而开发的新型热机械方法有望在实现基于石墨烯的下一代电子产品方面取得重大突破。该项目还将有助于促进石墨烯以及其他纳米材料缺陷分析和处理的变革进展。结合连续介质力学理论，研究结果将建立新的热-机械载荷与缺陷迁移率之间的本构方程，这将对改进现有石墨烯制造工艺和设计未来石墨烯以外的材料系统具有重要价值。在教育方面，拟议的研究将在大学和K-12水平上产生许多机会。宾夕法尼亚州立大学的研究生和本科生将从创新的、综合的实验操作和计算纳米力学的多学科研究经验中受益匪浅。pi将积极与宾夕法尼亚州立大学的几个组织合作，让包括女性和少数民族学生在内的代表性不足的群体参与拟议的研究项目。

Recent experiments have demonstrated that graphene, a monolayer of carbon atoms, exhibits surprisingly high room-temperature electron mobility. Such a remarkable electronic behavior may well enable ground-breaking advances in nanoelectronics when silicon-based technologies reach their natural limits imposed by fundamental physics. However, the control over the quality of graphene remains a major challenge because even a few atomic defects may markedly degrade the performance of a graphene device. The research team seeks to develop a novel thermo-mechanical method for perfecting graphene sheets by effectively removing defects through an integrated experimental and modeling effort. In particular, time-accelerated modeling methods will be developed to determine defect migration barriers and pathways and defect-defect reaction mechanisms under thermal and mechanical loadings. In parallel, experimental measurements of Raman topography, electrical transport, and low-temperature magnetotransport of suspended monolayer graphene devices will be performed before and after thermo-mechanical treatments, aiming at validating the modeling approaches and evaluating the effectiveness of the methods. The novel thermo-mechanical methods developed for perfecting graphene sheets are expected to lead to major breakthroughs toward realization of the graphene-based next-generation electronics. The project will also help foster transformative progress for the analysis and manipulation of defects in graphene as well as other nano-materials in general. When combined with continuum mechanics theories, the research results will establish new constitutive equations relating thermo-mechanical loading with defect mobility, which will be valuable for improving existing graphene manufacturing processes and for designing future materials systems beyond graphene. On the educational front, the proposed research will generate many opportunities at both the college and K-12 levels. Graduate and undergraduate students at Penn State will benefit greatly from the multidisciplinary research experience in innovative, integrated experimental manipulation and computational nano-mechanics. The PIs will actively work with several organizations at Penn State to involve underrepresented groups including women and minority students in carrying out proposed research program.