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.

项目概要 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运动是氧化还原活性位点功能的核心 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) 催化水分解反应，被视为 设计新的太阳能设备。该设计过程的一个关键部分是充分理解电子 较小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）通过结合电子 顺磁共振（EPR）实验与密度泛函理论（DFT）计算。 然而，我们发现将小低聚物与全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 直接计算小寡聚物的结果将可以更好地评估 计算与实验一致。确定什么泛函很重要 如果 DFT 计算用于指导太阳能电池设计，则适合。在目标 1 中，我们将 确定哪些泛函能够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，我们将确定真实的 通过比较跨越该范围的低聚物的结果来确定电荷离域的程度 建议离域长度。在这项工作结束时，我们将扩展 了解如何对电子捐赠系统进行建模并提供可用于 为新开发的太阳能设备建模，这将使此类设备在经济上更加可行 并减少我们对化石燃料的依赖。