Improving DFT Modeling of EPR Data for Small Molecule Organic Photovoltaics

改进小分子有机光伏 EPR 数据的 DFT 建模

• 批准号: 9277827
• 负责人: Kristy Lynn Mardis
• 金额: $ 9.77万
• 依托单位: CHICAGO STATE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-08-01 至 2020-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9277827
• 关键词: Active Sites; Agreement; Architecture; Biological Models; Carbon; Carbon Dioxide; Cells; Charge; Chemical Structure; Chemicals; Collaborations; Complex; Coupling; Data; Development; Devices; Electron Spin Resonance Spectroscopy; Electron Transport; Electrons; Energy-Generating Resources; Enzymes; Fossil Fuels; Fullerenes; Future; Genetic Recombination; Germanium; Global Warming; Goals; Grant; Harvest; Health Food; Hybrids; Ions; Knowledge; Length; Light; Metals; Methods; Minority; Modeling; Modification; Molecular Conformation; Molecular Models; Molecular Structure; Movement; Oxidation-Reduction; Photosynthesis; Planet Earth; Plants; Polymers; Process; Property; Publications; Reaction; Research; Research Personnel; Respiration; Role; Route; Science; Silicon; Solar Energy; Structure; Students; Sunlight; System; Testing; Transition Elements; Vertebral column; Water; Work; biological systems; career; computerized tools; density; design; electron donor; environmental change; experimental study; food security; fossil fuel energy; improved; molecular modeling; photosystem II; small molecule; theories; tool; undergraduate research; undergraduate student

PROJECT SUMMARY The movement of an electron from one redox active site to another is central to the function of many biological systems including respiration and photosynthesis. In natural photosynthesis, Photosystem II (PSII) catalyzes the water splitting reaction and is seen as a template for designing new solar devices. A critical part of this design process is to fully understand electron transfer processes in smaller model systems. We have recently investigated electron transfer in polymer-fullerene solar devices (bulk heterojunction solar cells) by combining electron paramagnetic resonance (EPR) experiments with density functional theory (DFT) calculations. However, we found that comparing small oligomers to experimental results of the full polymer system made interpretation of the results difficult. We hypothesize that comparing our DFT calculations directly to the results for small oligomers will allow a better assessment of the agreement between calculation and experiment. It is important to determine what functionals are suitable if DFT calculations are to be used to guide solar cell design. In Aim 1, we will determine which functionals adequately model oligomers that contain silicon and germanium as central atoms (rather than the more common carbon). In Aim 2, we will determine the true extent of charge delocalization by comparing results for oligomers that span the range suggested for delocalization lengths. At the conclusion of this work, we will have expanded knowledge of how to model electron donating systems and provided tools that can be used to model newly developed solar devices which will make such devices more economically viable and reduce our reliance on fossil fuels.

项目摘要 电子从一个氧化还原活性位点到另一个氧化还原活性位点的移动是氧化还原功能的核心。 许多生物系统包括呼吸和光合作用。在自然光合作用中， 光系统II（PSII）催化水裂解反应，并被视为一种模板， 设计新的太阳能设备这个设计过程的一个关键部分是充分理解电子 在更小的模型系统中的传输过程。我们最近研究了电子转移 聚合物-富勒烯太阳能器件（体异质结太阳能电池）， 顺磁共振（EPR）实验与密度泛函理论（DFT）计算。 然而，我们发现，将小的低聚物与完整聚合物的实验结果进行比较， 系统使结果的解释变得困难。我们假设比较我们的DFT 直接计算小的低聚物的结果将允许更好地评估 计算与实验的一致性。重要的是要确定哪些泛函 如果DFT计算用于指导太阳能电池设计，则是合适的。在目标1中，我们 确定哪些官能团充分模拟含有硅和锗的低聚物， 中心原子（而不是更常见的碳）。在目标2中，我们将确定 通过比较跨越范围的低聚物的结果来确定电荷离域的程度 建议用于离域长度。在这项工作结束时，我们将扩大 如何模拟电子捐赠系统的知识，并提供了可用于 模拟新开发的太阳能设备，使这些设备更经济可行 减少我们对化石燃料的依赖。