Collaborative Research: Chemical Control of Polymer/PbS Blends for PV Applications

合作提案：PI姓名：Moule（铅）提案编号：1436273机构：加州大学戴维斯分校PI姓名：Ganapathysubramanian提案编号：1437636机构：爱荷华州州立大学PI姓名：Ginger提案编号：1437016机构：华盛顿大学太阳代表地球上最丰富的无污染能源的潜在来源。基于集成到光伏（PV）器件中的有机聚合物的用于将光转换为电的太阳能电池如果能够提高太阳能转换效率，则为可再生电力生产提供了潜在的低成本途径。提高有机聚合物基太阳能电池效率的关键是更好地理解聚合物膜内材料的分子排列。该项目将应用新型电子显微镜工具来了解材料加工如何影响为光伏（PV）应用设计的聚合物/纳米颗粒薄膜中材料的三维排列。低成本的硫化铅（PbS）纳米粒子与导电聚合物的混合物将进行研究，因为这些混合物已显示出最近的高光伏效率，因为这些材料具有高的电子显微镜成像对比度。电子层析成像将生成混合物内材料的三维浓度图。这些图将用于将加工条件与聚合物/纳米颗粒膜内的材料排列相关联。然后将这些信息与器件性能相关联，以确定基于有机聚合物制造更好的太阳能电池的策略。这项工作将由一个合作团队进行，该团队将同时推进聚合物/纳米颗粒薄膜制造，三维电子显微镜成像和图像计算分析的科学，以揭示纳米级结构。这种协作方法有可能揭示光学和电子特性的结构起源，而这些特性是任何其他技术都无法测量的。关于扩大参与的教育和活动，该项目将提供多种外联和教育机会，包括通过男女童子军和4 H与儿童互动，在参加人数众多的地方节日进行公共教育，将研究材料纳入课堂，以及留住工科女生。该项目将开发和使用新的电子断层扫描工具，以了解材料加工如何影响为光伏（PV）应用设计的混合聚合物/纳米颗粒薄膜中材料的三维排列。低成本的硫化铅（PbS）纳米粒子与导电聚合物的混合物将进行研究，因为这些混合物已显示出最近的高光伏效率，因为这些材料具有高的电子显微镜成像对比度。电子显微镜工具是基于高角度环形暗场扫描电子断层扫描（HAADF-ET）与离散代数重建技术（DART）相结合，以生成三维（3D）材料浓度图，分辨率小于三立方纳米的混合有机/无机光伏材料。将使用基于图形的分析来测量3D数据的形态描述符的开发，包括相的数量、每个相中的浓度比、域尺寸、域连接性、路径的曲折度、各向异性和域表面积等特征。这些信息将被用来关联的形态，结构异质性，和物理分布的复合位点在混合的有机/无机电子薄膜的光电性能和光伏性能。关于扩大参与的教育和活动，该项目将提供多种外联和教育机会，包括通过男女童子军和4 H与儿童互动，在参加人数众多的地方节日进行公共教育，将研究材料纳入课堂，以及留住工科女生。

Proposals in Collaborative:PI Names: Moule (Lead)Proposal No: 1436273Institution: University of California, Davis PI Name: GanapathysubramanianProposal No:1437636 Institution: Iowa State UniversityPI Name: Ginger Proposal No: 1437016 Institution: University of WashingtonThe sun represents the most abundant potential source of pollution-free energy on earth. Solar cells for conversion of light to electricity based on organic polymers integrated into a photovoltaic (PV) device offer a potentially low-cost route for renewable electricity production if the solar energy conversion efficiency can be improved. The key to improving the efficiency of organic polymer based solar cells is to better understand the molecular arrangement of the materials within the polymer film. This project will apply novel electron microscopy tools to understand how materials processing affects the three-dimensional arrangement of materials in polymer/nanoparticle films designed for photovoltaic (PV) applications. Mixtures of low-cost lead sulfide (PbS) nanoparticles with electrically conducting polymers will be studied because these mixtures have shown recent high photovoltaic efficiency, and because these materials have high imaging contrast by electron microscopy. The electron tomography will generate three dimensional concentration maps of materials within the mixture. These maps will be used to correlate processing conditions to material arrangement within the polymer/nanoparticle film. This information will then be correlated to device performance in order to identify strategies for making better solar cells based on organic polymers. The work will be carried out by a collaborative team that will simultaneously advance the science of polymer/nanoparticle film fabrication, three dimensional electron microscope imaging, and computational analysis of the images to reveal nanoscale structure. This collaborative approach has the potential uncover the structural origin of optical and electronic properties that cannot be measured by any other technique. With respect to education and activities for broadening participation, the project will provide a diverse set of outreach and educational opportunities that include interaction with children through the Boys and Girls Scouts and 4H, public education at well attended local festivals, inclusion of research material in classes, and retention of female engineering students. Technical Description This project will develop and use new electron tomography tools to understand how materials processing affects the three-dimensional arrangement of materials in hybrid polymer/nanoparticle films designed for photovoltaic (PV) applications. Mixtures of low-cost lead sulfide (PbS) nanoparticles with electrically conducting polymers will be studied because these mixtures have shown recent high photovoltaic efficiency, and because these materials have high imaging contrast by electron microscopy. The electron microscopy tool is based on high-angle annular dark-field scanning electron tomography (HAADF-ET) combined with the discrete algebraic reconstruction technique (DART) to generate three-dimensional (3D) material concentration maps with resolution of less than three cubic nanometers for the hybrid organic/inorganic photovoltaic materials. Development of morphology descriptors of the 3D data, including features like the number of phases, concentration ratio in each phase, domain size, domain connectivity, tortuosity of pathways, anisotropy and domain surface area will be measured using graph-based analysis. This information will be used to correlate morphology, structural heterogeneity, and physical distribution of recombination sites in mixed organic/inorganic electronic films to optoelectronic properties and photovoltaic performance. With respect to education and activities for broadening participation, the project will provide a diverse set of outreach and educational opportunities that include interaction with children through the Boys and Girls Scouts and 4H, public education at well attended local festivals, inclusion of research material in classes, and retention of female engineering students.