FRG: Collaborative Research: Modeling and Computation of Crystalline Nanostructures

FRG：合作研究：晶体纳米结构的建模和计算

• 批准号: 0854870
• 负责人: Peter Smereka
• 金额: $ 44.05万
• 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: 2009
• 资助国家: 美国
• 起止时间: 2009-07-01 至 2014-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0854870&HistoricalAwards=false
• 关键词: FRG; Collaborative; Research; Modeling; Computation; FRG; Collaborative; Research; Modeling; Computation

This project is aimed at advancing the state of the art for simulating nanocrystalline materials. A common technique to manufacture such materials is depositing a monocrystalline film on a monocrystalline substrate of a different composition (heteroepitaxy); in the process elastic interactions are very important. The project will develop highly efficient computational tools by combining continuum mechanics to handle long-range elastic interactions with kinetic Monte Carlo (KMC) simulations that can accurately describe transport kinetics at the atomic level. The methods developed will be broadly applicable, but the immediate focus is on quantum dot nano-structures. Three different approaches will be used to accomplish this task. One of these will use KMC to deduce various parameters used in continuum models. Another approach will be based on a new formulation of KMC which can be shown, using statistical mechanics, to be connected with the chemical potential. This will allow a fairly seamless connection between our KMC formulation and continuum mechanics. We can exploit this connection to use KMC on small, well separated regions and then combine these regions together using macroscopic variables, such as atomic flux and elastic displacement fields. Another approach is to perform KMC everywhere but using coarse-grained continuum fields that are updated on a macroscopic time scale.Nanocrystalline materials have shown great promise for many applications such as solid state lasers, memory devices, and photovoltaic cells. It is anticipated that the modeling and computation methods developed in this research will pave the way for performing device level simulations and provide valuable guidance in the interpretation of experimental measurements for strained alloy systems. Our group has close ties with experimental groups based in the semiconductor industry and academia, which will allow us to assess our modeling progress.

该项目旨在推进模拟纳米晶体材料的最新技术。制造此类材料的一种常见技术是将单晶膜沉积在不同组成（Heteroepitaxy）的单晶底物上；在此过程中，弹性相互作用非常重要。该项目将通过将连续力学与动力学蒙特卡洛（KMC）模拟进行远程弹性相互作用来开发高效的计算工具，从而可以准确地描述原子水平的传输动力学。 开发的方法将广泛适用，但是直接的重点是量子点纳米结构。将使用三种不同的方法来完成此任务。其中之一将使用KMC推断连续模型中使用的各种参数。 另一种方法将基于一种新的KMC公式，可以使用统计力学与化学潜力相关。这将允许我们的KMC公式和连续机械之间的相当无缝的联系。我们可以利用这种连接将KMC在较小的，分离良好的区域上使用，然后使用宏观变量（例如原子通量和弹性位移场）将这些区域组合在一起。另一种方法是在各地执行KMC，但是使用在宏观时间尺度上进行更新的粗粒细粒度连续性场。纳米晶体材料对许多应用显示了诸如固态激光器，存储器和光伏电池等许多应用的巨大希望。预计本研究中开发的建模和计算方法将为执行设备级别的模拟铺平道路，并在解释紧张​​的合金系统实验测量时提供宝贵的指导。我们的小组与基于半导体行业和学术界的实验小组有着密切的联系，这将使我们能够评估建模进度。