BRIGE: Photovoltaic Mapping of Gradients to Determine Structure-Function Relationships in Organic and Nanocrystalline Solar Cells

技术描述：有机和纳米晶体太阳能电池所需的活性材料比其他薄膜电池少一个数量级。光伏设备。这个bridge项目将引入一个新的实验框架来研究有机太阳能电池，有三个目标：(1)提高从有机和纳米晶体太阳能电池中获得的数据的质量和可重复性；(2)大大减少表征它们所需的时间和资源；最终(3)提高它们的光伏效率。该框架的核心是在半导体薄膜内产生成分或形态梯度，并使用一种新型的非破坏性液态金属探针测量这些梯度的空间分辨光伏“图”。我们将提出的技术称为梯度的光伏映射（PVMAP）。PVMAP一旦开发出来，就可以用来提出关于超薄光伏薄膜的假设，而这些假设无法通过系列技术进行测试。PVMAP将用于确定半导体聚合物-富勒烯复合薄膜的熔融温度以下的热退火在多大程度上增加了与电极垂直的堆叠轴取向的晶体的比例。PVMAP还可以通过不同梯度的迭代映射（类似于“定向进化”）用于有机太阳能电池的系统优化。更广泛的意义和重要性：在过去五年中，全球光伏发电容量以每年60%的速度增长。这种趋势的延续需要以低成本高效运行的新设备。一个候选是基于塑料材料的太阳能电池板。这些器件还不能与硅基器件竞争的原因之一是，目前的实验技术还不能有效地理解它们的操作细节。这个项目将使研究人员能够比目前更快地收集有关有机太阳能电池的信息。该技术通过在单个设备中结合多种材料和特性来工作，其中包含不同特性组合的不同区域可以单独测量。该提案的技术部分，连同其整合研究、教育和为代表性不足的学生提供机会的努力，将有助于修复环境，并在包括可再生能源在内的经济中创造就业机会。扩大参与活动：PI是加州大学圣地亚哥分校纳米工程系的多元化官员。该提案将支持：(1)为IDEA（多样性）中心的学者提供带薪暑期实习；(2)针对圣地亚哥拉美裔社区中学生的外展活动；(3)由加州大学圣地亚哥分校女工程师协会主办的一个面向高中女生的项目。第四项努力侧重于这些活动对参与者的教育和职业选择的结果。PI将与加州大学圣地亚哥分校的IDEA中心合作开发调查，定期发送给参与者。结果和定量分析将提交给同行评审的期刊，如工程教育杂志。定量了解导致代表性不足的学生从事科学和工程职业的因素（以及导致他们退出或改变领域的因素）对PI扩大机会的努力至关重要，并将在能够从国家科学基金会获得额外科学项目和创新项目的资助以扩大参与方面发挥重要作用。这项研究是由工程教育和中心部的工程项目扩大参与计划的一部分，即工程项目扩大参与研究启动基金资助的。

Technical description:Organic and nano-crystalline solar cells require an order of magnitude less active material than other ?thin-film? photovoltaic devices. This BRIGE project will introduce a new experimental framework in which to study organic solar cells, with three goals: (1) to improve the quality and reproducibility of data obtained from organic and nanocrystalline solar cells, (2) to reduce drastically the time and resources needed to characterize them, and ultimately (3) to increase their photovoltaic efficiencies. At the core of the proposed framework are the generation of compositional or morphological gradients within semiconductor thin films and the measurement of spatially resolved photovoltaic "maps" of these gradients using a new type of non-damaging liquid metal probe. We refer to the proposed technique as photovoltaic mapping (PVMAP) of gradients. PVMAP, once developed, can be used to pose hypotheses about ultrathin photovoltaic films that cannot be tested using serial techniques. PVMAP will be used to determine the extent to which thermal annealing below the melting temperature of a semiconducting polymer-fullerene composite film increases the fraction of crystallites oriented with their ð-stacking axes perpendicular to the electrodes. PVMAP can also be used for the systematic optimization of organic solar cells by iterative mapping of different gradients (analogous to "directed evolution").Broader significance and importance:Global capacity for photovoltaic electricity has increased at a rate of sixty percent per year for the last five years. Continuation of this trend requires new devices that operate with high efficiencies at low cost. One candidate is solar panels based on plastic materials. One of the reasons that these devices are not yet competitive with those based on silicon is that the details of their operation cannot be understood efficiently using current experimental techniques. This project will allow researchers to gather information about organic solar cells much more quickly than is currently possible. The proposed technique works by combining many materials and characteristics in a single device, in which different areas containing different combinations of properties can be measured separately. The technical portion of this proposal, along with its efforts to integrate research, education, and opportunity for underrepresented students, will help remediate the environment and create jobs in an economy that includes renewable energy.Broadening Participation activities:The PI is the Diversity Officer in the Department of NanoEngineering at UCSD. This proposal would support: (1) paid summer internships for IDEA (Diversity) Center Scholars; (2) an outreach event for middle school students from predominantly Hispanic neighborhoods in San Diego; and (3) a program for high school girls hosted by the UCSD Society for Women Engineers. A fourth effort focuses on the outcomes of these activities on the educational and career choices of participants. The PI will work with the IDEA Center at UCSD to develop surveys, sent periodically to participants. Results and a quantitative analysis will be submitted to a peer-reviewed journal, such as the Journal of Engineering Education. A quantitative understanding of the factors that lead underrepresented students toward careers in science and engineering (and the factors that cause them to withdraw or change fields) will be critical to the PI's efforts to expand opportunity and will play a major role in being able to secure funding from NSF for additional scientific projects and for innovative programs to broaden participation.This research has been funded through the Broadening Participation Research Initiation Grants in Engineering solicitation, which is part of the Broadening Participation in Engineering Program of the Engineering Education and Centers Division.