CDS&E:Collaborative Research: Multiscale Modeling, Simulation and Optimization for Designing Organic Solar Cells

CBET 1404591/1404655Li/千太阳能供应是可再生的、充足的、环保的。它相对没有与化石燃料或核能相关的问题，如增加燃料成本、废物处理、散热、安全问题和温室气体排放。太阳能电池是光伏发电系统的关键部件，可以将太阳能直接转化为电能。虽然当今的太阳能发电技术主要是硅基材料，但有机太阳能电池(OSCs)由于其制造成本低，以及在柔性结构中部署的潜力而受到越来越多的关注。然而，到目前为止，由于对OSCs长度尺度上的电荷传输行为的了解有限，OSCs的能量效率一直受到阻碍；然而，这种传输对于器件效率是至关重要的。由于几乎无限多的材料组合和工艺条件，目前用于OSC优化的试错方法经常失败。因此，这项合作研究的目标是开发一种多尺度模拟和优化OSCS的方法，该方法直接将基本材料属性(电子和光学)、纳米级形态及其对加工条件(例如温度和时间)、块状材料属性(例如体迁移率)和器件设计的依赖关系与器件效率联系起来。这项研究的成功完成将为有机电子在能源转换中的商业化铺平一条可行的道路，这将在美国各地产生绿色电力和就业机会。这项拟议的研究旨在通过连续的整合步骤，在多个时间和长度尺度上合并模拟工具。由此产生的工具将实现一种整体设计方法，其中将系统地探索设计空间，以显着提高OSC设备的性能。这种整体方法结合了实验验证，以改进每个尺度(微观、细观和宏观)的模拟，并最终验证优化结果。更具体地说，这项研究将通过表征纳米级的形态、测量整体迁移率和测试设备来验证多尺度模拟。然后，PI将通过代理建模和多尺度模型的灵敏度分析来优化OSC的设计和制造工艺，以实现高效率。这项研究的成功完成将填补有机电子学研究中的一个关键知识空白，并将通过考虑电荷传输和材料性质的多尺度耦合以及通过在每个尺度上的实验验证来形成有机电子的新的模拟范例。本项目中微观和宏观尺度之间的桥梁方案将为其他类型的太阳能电池和能源设备(如超级电容器和电池)的多尺度模拟和优化树立榜样。这些模型和模拟的结果将导致更合理的设计和在OSC方面取得重大技术进步的更大潜力。

CBET 1404591/1404655Li/QianSolar energy supply is renewable, abundant, and environmentally benign. It is relatively free of problems associated with fossil fuels or nuclear energy, such as increasing fuel costs, waste disposal, heat dissipation, safety concerns, and the release of greenhouse gases. The solar cell is the key component of photovoltaic systems, which can directly convert the solar energy into electricity. While solar electricity generation technologies of today are dominated by silicon based materials, organic solar cells (OSCs) have attracted growing attention due to their low cost in fabrication, and their potential to be deployed in flexible structures. However, the energy efficiency of OSCs has thus far been impeded due to limited understanding of charge transport behaviors across length scales of OSCs; yet, such transport is crucial for device efficiency. The current try-and-error approach for optimization of OSC often fails due to nearly-infinite number of material combinations and processing conditions. The objective of this collaborative research is thus to develop a multiscale simulation and optimization methodology for OSCs that directly links the basic materials properties(electronic and optical), nanoscale morphology and their dependency on processing conditions (e.g. temperature and time), bulk material properties (e.g. bulk mobility), and device designs, to device efficiency. Successful completion of this research will pave a viable pathway for commercializing organic electronics in energy conversion, which can generate both green electricity and jobs throughout the United States. The proposed research aims to merge simulation tools across multiple time and length scales using successive integration steps. The resulting tools would enable a holistic design approach where the design space will be systematically explored to dramatically improve the performance of OSC devices. Such a holistic approach integrates experimental validations to refine the simulations at each scale (micro, meso, and macro) and ultimately to verify the optimization results. More specifically, the research will verify the multiscale simulation by characterizing nanoscale morphology, measuring bulk mobility, and testing the devices. The PIs will then optimize the designs and fabrication processes of OSCs for high efficiency through surrogate modeling and sensitivity analysis of the multiscale models. Successful completion of this research will fill a critical knowledge gap in organic electronics research and will form a new simulation paradigm for organic electronics by accounting for multiscale coupling in charge transport and material properties and by experimental validation at each scale. The scheme to bridge the micro and macro scales in this project will set an example for multiscale simulation and optimization of other type of solar cells and energy devices such as super-capacitors and batteries. The results of these models and simulations will lead to more rational designs and greater potential for significant technological advances in OSCs.