FRG: Development and Validation of Novel Computational Tools for Modeling the Growth and Self-Assembly of Crystalline Nanostructures

FRG：用于模拟晶体纳米结构的生长和自组装的新型计算工具的开发和验证

• 批准号: 1105409
• 负责人: Katsuyo Thornton
• 金额: $ 90万
• 依托单位: Regents of the University of Michigan - Ann Arbor
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-09-15 至 2015-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1105409&HistoricalAwards=false
• 关键词: FRG; Development; Validation; Novel; Computational

TECHNICAL SUMMARY:This award supports theoretical research and educational activities in computational materials science, with a focus on the controlled growth of nanostructured materials.Nanostructured materials, including semiconductor quantum dots and nanowires, hold the promise to yield revolutionary new technologies. The realization of this promise has been hindered to date by the challenges inherent in reproducibly synthesizing and assembling arrays of such nanostructures with controlled morphologies and compositions. Computational modeling is essential for understanding the complex fundamental processes underlying nanostructure growth and self-assembly. However, current state-of-the-art computational methods are not well suited to such studies because of the difficulty in accounting for the atomistic processes that control growth, while simulating over the larger length and time scales associated with self-assembly. The PIs, three materials scientists and a mathematician, propose to develop a new computational methodology that addresses these issues, in order to investigate quantum-dot formation in thin-film heteroepitaxy and nanowire growth mediated by liquid catalysts. This multidisciplinary project addresses the challenge of understanding multiscale phenomena associated with the formation of nanostructures by exploiting recent developments in phase field crystal (PFC) models, which resolve atomic spatial scales on diffusive time scales. The PFC method naturally incorporates elastic/plastic deformations and crystalline defects, and has already been used to simulate interfacial evolution during solid-liquid phase transitions. The team will develop a new PFC-based computational methodology for modeling solid-vapor, liquid-vapor and faceted solid-liquid interfaces, which are commonly present during the growth of crystalline nanostructures. The models will be parameterized and validated with the aid of atomistic simulations and experimental results. Amplitude/phase equations similar to traditional phase field models will be derived to allow larger domains to be simulated. This will reveal how atomistic features and processes affect morphological evolution at larger scales. We will develop new efficient numerical algorithms that will enable simulations of large 3D systems, as well as novel tools for data extraction and visualization. These tools will advance the field of computational materials science by providing a framework for the computational discovery of the fundamental mechanisms underlying synthesis and assembly of nanostructures.Courses on crystal growth for high school students are planned as part of the California State Summer School for Mathematics and Science at UC Irvine, along with additional outreach activities at the Ann Arbor Hands-On Museum. 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, enhancing their educational experiences. Furthermore, a symposium on the PFC approach will be organized. In collaboration with the National Institute of Standards and Technology, a FiPy version of the PFC codes will be developed and will be disseminated through their website for use in education and research.NON-TECHNICAL SUMMARY:This award supports theoretical research and educational activities in computational materials science, with a focus on the controlled growth of nanostructured materials.Artificial materials composed of building blocks on the scale of some ten thousand times smaller than the width of a human hair but still larger than an atom can have unique properties and capabilities that differ dramatically from bulk crystalline materials. The properties of these nanostructured materials and their lean tiny cousins, nanostructures, can be controlled through the way the building blocks are arranged; they may even arrange themselves through a process of self-assembly. Nanostructured materials including semiconductor quantum dots and nanowires, hold the promise to yield revolutionary new technologies. Realizing this promise has been hindered by difficulties in controlling their structures and compositions. The use of computers to model nanostructures and nanostructured materials is essential for understanding the complex fundamental processes underlying nanostructure growth and self-assembly. However, current state-of-the-art computational methods are not well suited to such studies because of the difficulty in accounting for the atomic scale processes that control growth, while simulating over the larger length and time scales associated with self-assembly, involving the organization of the building blocks. This grant will support the development of a new computational methodology that addresses these issues, in order to investigate quantum-dot formation and nanowire growth. The team will also develop new efficient numerical algorithms that will enable simulations of large three-dimensional systems, as well as novel tools for data extraction and visualization. These tools will advance the field of computational materials science by providing a framework for computational discovery of the fundamental mechanisms underlying synthesis and assembly of nanostructures.Courses on crystal growth for high school students are proposed as part of the California State Summer School for Mathematics and Science at UC Irvine, and additional outreach activities are planned at the Ann Arbor Hands-On Museum. 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, enhancing their educational experiences. Furthermore, a symposium on aforementioned computational techniques will be organized. In collaboration with the National Institute of Standards and Technology, a Python-script version of the simulation software will be developed and will be disseminated through their website for use in education and research.

技术摘要：该奖项支持计算材料科学中的理论研究和教育活动，重点是纳米结构材料的受控增长。纳米结构材料，包括半导体量子点和纳米线，有望产生革命性的新技术。迄今为止，由于具有控制的形态和组成的这种纳米结构的可重复合成和组装阵列固有的挑战，这一诺言的实现受到了阻碍。计算建模对于理解纳米结构生长和自组装的基本过程的复杂基本过程至关重要。但是，由于难以计算控制增长的原子过程，同时模拟与自组装相关的较大长度和时间尺度，因此当前的最新计算方法不适合此类研究。 PIS是三位材料科学家和一名数学家，提议开发一种解决这些问题的新计算方法，以研究薄膜杂型杂质中的量子点形成和液体催化剂介导的纳米线生长。该多学科项目通过利用相位场晶体（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，该模型可以解决扩散时间尺度上的原子空间量表。 PFC方法自然结合了弹性/塑性变形和晶体缺陷，并且已经用于模拟固液相变过的界面进化。该团队将开发一种新的基于PFC的计算方法，用于建模固体蒸气，液体蒸气和固定液液体接口，这些界面通常是在结晶纳米结构的生长过程中。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。将得出与传统相位场模型相似的振幅/相位方程，以允许模拟较大的域。这将揭示原子特征和过程如何影响较大尺度的形态演化。我们将开发新的有效的数值算法，这些算法将启用大型3D系统的模拟，以及用于数据提取和可视化的新工具。这些工具将通过为计算纳米结构的综合和组装的基本机制提供一个框架来推动计算材料科学领域。计划在UC Irvine的加利福尼亚州立大学数学和科学的一部分中为高中生的水晶增长提供额外的纳米结构。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，从而增强他们的教育经验。此外，将组织PFC方法上的研讨会。 通过与国家标准技术研究所合作，将开发PFC代码的FIPY版本，并将通过其网站进行分解，以用于教育和研究中。没有技术摘要：该奖项支持理论研究和教育活动，以计算材料科学，重点是纳入人工材料的受控材料，该材料的范围更大。原子可以具有独特的特性和功能，这些特性和功能与大量晶体材料截然不同。这些纳米结构材料的特性及其瘦小的堂兄纳米结构可以通过布置构建块的方式来控制；他们甚至可以通过自我组装过程来安排自己。包括半导体量子点和纳米线在内的纳米结构材料，承诺产生革命性的新技术。在控制其结构和组成方面的困难使人们意识到这一诺言受到了阻碍。 使用计算机对纳米结构和纳米结构材料进行建模，这对于理解纳米结构生长和自组装的复杂基本过程至关重要。但是，由于难以在控制增长的原子量表过程中，同时模拟与自组装相关的较大长度和时间尺度，涉及构建基金会的组织。该赠款将支持一种解决这些问题的新计算方法论，以研究量子点形成和纳米线增长。该团队还将开发新的有效的数值算法，这些算法将启用大型三维系统的模拟，以及用于数据提取和可视化的新型工具。 These tools will advance the field of computational materials science by providing a framework for computational discovery of the fundamental mechanisms underlying synthesis and assembly of nanostructures.Courses on crystal growth for high school students are proposed as part of the California State Summer School for Mathematics and Science at UC Irvine, and additional outreach activities are planned at the Ann Arbor Hands-On Museum.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，从而增强他们的教育经验。此外，将组织关于上述计算技术的研讨会。 将与国家标准技术研究所合作，将开发模拟软件的Python-Script版本，并将通过其网站传播以供教育和研究中使用。