FRG: Predictive Computational Modeling of Two-Dimensional Materials Beyond Graphene: Defects and Morphologies

FRG：石墨烯以外的二维材料的预测计算模型：缺陷和形态

• 批准号: 1507033
• 负责人: Katsuyo Thornton
• 金额: $ 109.74万
• 依托单位: Regents of the University of Michigan - Ann Arbor
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-09-15 至 2019-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1507033&HistoricalAwards=false
• 关键词: FRG; Predictive; Computational; Modeling; Two

NONTECHNICAL SUMMARYThe Division of Materials Research and the Division of Mathematical Sciences contribute funds to this award. It supports interdisciplinary research and educational activities in computational materials science, with a focus on the growth of two-dimensional (2D) semiconducting materials. While graphene is the best-known 2D material, it is limited in device application due to its high conductivity. More recent research has focused on 2D semiconducting materials, which can be manipulated to block or permit current flow. These research activities have been primarily based on experimental explorations due to a gap in the fundamental understanding in what determines their structures and properties. This project aims to help fill this gap by developing a model for the growth of these systems based on the phase field crystal modeling approach. This approach allows researchers to study materials involving tiny structures as small as atoms. The team of researchers will develop, parameterize, and validate a phase field crystal model for 2D semiconducting materials, which can be used improve the synthesis process of 2D materials and their assembly. Simulations will also be used to examine the structure of these materials and associated defects at the atomic level. Educational activities include courses on crystal growth for high school students, proposed as part of the California State Summer School for Mathematics and Science at UC Irvine, engaging with Science Olympiad, and other STEM events. These activities will help develop the future generation of mathematicians, scientists and engineers. Graduate students will receive interdisciplinary training and will present their findings at conferences, which will enhance their educational experience. The team shall also act as a resource for the research community by distributing the codes that are developed and by organizing symposia on phase field crystal models at national meetings.TECHNICAL SUMMARYThe Division of Materials Research and the Division of Mathematical Sciences contribute funds to this award. It supports interdisciplinary research and educational activities in computational materials science, with a focus on the growth of two-dimensional (2D) semiconducting materials. The recent discovery of two-dimensional (2D) semiconducting materials such as MoS2 and MoSe2 has intensified the research efforts in these materials. These materials exhibit unique properties due to the 2D confinement, but they, unlike graphene, also possess the ability to switch between conducting and insulating states, offering a potential to yield revolutionary new technologies. The research efforts have been primarily based on experimental exploration based on various synthetic routes, and significant gaps exist in the fundamental understanding of what determine their bulk and defect structures and morphologies, as well as how they influence their properties. Due to the small length scale involved, computational modeling is essential for developing such understanding. Phase field crystal (PFC) modeling is uniquely suited for this problem because of its ability to resolve atomic-scale structure and its extended time-scale comparable to those associated with synthesis. This multidisciplinary project addresses the challenge of understanding multiscale phenomena associated with the formation of nanostructures by exploiting recent developments in PFC models, which follow the dynamics of individual atoms over diffusive time scales. Originating from classical density functional theory, the PFC method naturally incorporates elastic and plastic deformations as well as crystalline defects. The team of materials scientists and a mathematician will develop a new PFC-based computational methodology for modeling the structure and the synthesis of two-dimensional, multicomponent materials. The models will be parameterized and validated with the aid of atomistic simulations and experimental results. Defects such as grain boundaries, which must be controlled in device applications, will be examined. The computational tools will build on the efficient numerical algorithms developed under previous funding and tailor it to the new models and will be disseminated through repositories such as GitHub. These tools will provide a framework for the computational discovery of the fundamental mechanisms underlying synthesis of 2D materials, their assembly, and their atomic-scale structure. Educational activities include courses on crystal growth for high school students, proposed as part of the California State Summer School for Mathematics and Science at UC Irvine, engaging with the Science Olympiad, and other STEM events. These activities will help develop the future generation of mathematicians, scientists and engineers. Graduate students will receive interdisciplinary training and will present their findings at conferences, which would enhance their educational experience. The group shall also act as a resource for the research community by organizing symposia on phase field crystal models at national meetings.

非技术总结材料研究和数学科学划分为该奖项贡献了资金。它支持计算材料科学中的跨学科研究和教育活动，重点是二维（2D）半导体材料的增长。 尽管石墨烯是最著名的2D材料，但由于其高电导率，它在设备应用中受到限制。 最近的研究集中在2D半导体材料上，可以操纵以阻止或允许电流流动。 这些研究活动主要基于实验探索，这是由于决定其结构和特性的基本理解差距。 该项目旨在通过基于相位晶体建模方法为这些系统增长的模型开发模型来帮助填补这一空白。 这种方法使研究人员可以研究涉及与原子小的微小结构的材料。 研究人员团队将开发，参数化和验证2D半导体材料的相场晶体模型，可用于改善2D材料及其组装的合成过程。 模拟还将用于检查原子水平上这些材料的结构和相关的缺陷。 教育活动包括有关高中生水晶增长的课程，作为加州大学欧文分校的加利福尼亚州立大学数学和科学暑期学校的一部分，与科学奥林匹克运动和其他STEM活动一起参与。 这些活动将有助于发展未来的数学家，科学家和工程师。 研究生将接受跨学科培训，并将在会议上提出他们的发现，这将增强他们的教育经验。该团队还应通过分发开发的代码并在国家会议上组织阶段晶体模型的研讨会来充当研究社区的资源。技术摘要材料研究部和数学科学部门为该奖项贡献了资金。它支持计算材料科学中的跨学科研究和教育活动，重点是二维（2D）半导体材料的增长。最近发现的二维（2D）半导体材料（例如MOS2和MOSE2）增强了这些材料的研究工作。 这些材料由于2D限制而表现出独特的特性，但与石墨烯不同，它们也具有在传导和绝缘状态之间切换的能力，具有产生革命性新技术的潜力。 研究工作主要基于基于各种综合途径的实验探索，并且在对决定其批量和缺陷结构和形态的基本理解中存在很大的差距，以及它们如何影响其性质。 由于涉及较小的长度，计算建模对于发展这种理解至关重要。 相位场晶体（PFC）建模非常适合此问题，因为它可以解决原子尺度结构及其与合成相关的结构的扩展时间尺度。这个多学科项目通过利用PFC模型中的最新发展来解决与纳米结构形成相关的多尺度现象的挑战，PFC模型遵循各个原子的动态，而不是扩散时间尺度。 PFC方法源自经典密度功能理论，自然结合了弹性和塑性变形以及晶体缺陷。 材料科学家和数学家团队将开发一种新的基于PFC的计算方法，用于建模二维，多组分材料的结构和合成。 这些模型将在原子模拟和实验结果的帮助下进行参数化和验证。 将检查必须在设备应用中控制诸如晶界之类的缺陷。 计算工具将建立在先前资金下开发的有效数值算法的基础上，并将其量身定制到新模型，并通过GitHub等存储库进行传播。 这些工具将为2D材料，组装及其原子尺度结构的基本机制的计算发现提供一个框架。 教育活动包括有关高中生水晶增长的课程，并作为加州大学欧文分校的加利福尼亚州立大学数学和科学学院的一部分，参与科学奥林匹克运动会以及其他STEM活动。 这些活动将有助于发展未来的数学家，科学家和工程师。 研究生将接受跨学科培训，并将在会议上提出他们的发现，这将增强他们的教育经验。 该小组还应通过在国家会议上组织阶段晶体模型的研讨会来充当研究社区的资源。