Phase field methods, parameter identification and process optimisation

相场方法、参数识别和工艺优化

• 批准号: 511588106
• 负责人: Professor Dr. Roland Herzog
• 金额: --
• 依托单位: Interdisziplinäres Zentrum für Wissenschaftliches Rechnen (IWR)
• 依托单位国家: 德国
• 项目类别: Research Units
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/511588106?language=en
• 关键词: Phase; field; methods; parameter; identification

This project aims at a) the derivation of accurate mathematical models for the morphology formation during organic solar cell production, both via spin coating and printing processes, b) to develop efficient numerical schemes that allow for the fast and accurate numerical simulation of these models in two and three spatial dimensions, and c) the use of parameter identification techniques to calibrate the models using experimental data obtained by other projects within the research unit.The modelling methodology will be based on phase field descriptions of binary polymer-NFA systems whose dynamics is governed by a free energy functional based on the Flory-Huggins theory. Evaporation of the solvent will be taken into account by introducing an additional order parameter, allowing for a flexible treatment of geometric effects but also a natural coupling to hydrodynamics. In addition, appropriate mobilities will take care of size exclusion effects that occur when most of the solvent is evaporated.The efficient numerical schemes we will develop in this proposal are essential for evaluating the complex phase-field models. In order to achieve the desirable accuracy, the discretization needs to be sufficiently fine-grained requiring the solution of many large-scale (non)linear systems of equations. The efficiency will rely on developing suitable iterative solution schemes requiring structured preconditioners.Relying on these algorithms, parameter identification is carried out by numerically solving appropriate non-linear least squares problems. As the specific morphology is very sensitive to the initial conditions and the choice of parameters, yet the efficiency of the resulting organic solar cells mostly depends on averaged quantities, it is most important to develop appropriate loss functionals for the purpose of parameter identification. In addition, a sensitivity analysis will be carried out to identify the most important parameters in terms of these quantities of interest.

该项目旨在a)通过旋转涂层和印刷工艺推导有机太阳能电池生产过程中形态形成的精确数学模型，b)开发有效的数值方案，允许在二维和三维空间中快速准确地对这些模型进行数值模拟，以及c)使用参数识别技术根据研究单位内其他项目获得的实验数据校准模型。建模方法将基于二元聚合物- nfa系统的相场描述，其动力学由基于Flory-Huggins理论的自由能泛函数控制。溶剂的蒸发将通过引入一个额外的阶参数来考虑，允许对几何效应进行灵活的处理，同时也考虑到流体力学的自然耦合。此外，适当的流动性将照顾到大多数溶剂蒸发时发生的尺寸排除效应。我们将在本提案中开发的有效数值格式对于评估复杂相场模型是必不可少的。为了达到理想的精度，离散化需要足够细粒度，需要求解许多大型（非线性）方程组。效率将依赖于开发合适的迭代解决方案，需要结构化的前置条件。基于这些算法，通过数值求解适当的非线性最小二乘问题进行参数辨识。由于特定的形态对初始条件和参数的选择非常敏感，而所得有机太阳能电池的效率主要取决于平均量，因此开发合适的损失函数来识别参数是最重要的。此外，将进行敏感性分析，以确定这些有关数量的最重要参数。