Modeling the Charge Transport of Nanowire-based Dye-Sensitized Solar Cells

基于纳米颗粒薄膜的传统染料敏化太阳能电池（DSSC）的效率受到电子注入与来自界面电荷复合和背反应的损耗机制之间的竞争的限制。 在没有将电子驱动到集电器的局部场的情况下，界面电子可以与光活性染料复合或与电解质反向反应。 这些不期望的损耗限制了光电阳极的厚度和最大转换效率。 纳米线阵列是有前途的架构，其由于电场而具有改善的电子传输和电荷注入。 然而，DSSC设备的基础上基于纳米线的光阳极迄今还不能充分利用的好处，纳米线提供的电子传输，短路电流，和开路电压。 本提案的目的是开发一个模型，模拟的性能，基于锗的DSSC，使这些设备内的场辅助电荷传输效应可以被理解和更有效地使用。 拟议的工作将侧重于结合电荷传输模型，该模型考虑了界面电场与实验研究，以验证传输动力学和转换效率计算的基于硅藻土的DSSC。 用于制造半导体氧化物纳米线的阳极-氧化铝-氧化物模板法利用了制备具有不同类型材料、纵横比和间距的纳米线的极大灵活性。 这种灵活性允许系统地研究场辅助电子输运对DSSC效率的影响。 所开发的模型可用于确定所需的制造参数（即纳米线直径，壳厚度，长度和阵列密度），以最大限度地提高效率。 这些结果也可能提供新的洞察到控制的关键反应或过程中的电荷传输DSSCs.Broader ImpactsBeyond光伏应用，纳米线阵列的发展是重要的电子，光电，环境和生物医学应用。 拟议的教育和推广活动利用佛罗里达大学（UF）现有的成功计划。 通过以前的NSF CCLI（课程，课程和实验室改进）补助金在UF开发的纳米技术工程课程序列将得到加强，包括太阳能光伏。 本科生参与拟议的研究的机会将通过UF大学学者计划提供。 来自代表性不足的群体的学生将通过与PI在拟议的研究背景下的互动辅导用友大学少数民族辅导计划。 可再生能源和纳米材料学校教师的短期课程将通过UF教师学者计划提供。 高中学生将通过UF学生科学培训计划招募夏季经验。

1033736ZieglerIntellectual MeritEfficiencies of traditional dye-sensitized solar cells (DSSCs) based on nanoparticle thin films are limited by the competition between electron injection and the loss mechanisms from interfacial charge recombination and back reactions. Without a localized field driving electrons to the current collector, interfacial electrons can recombine with the photoactive dye or back-react with the electrolyte. These undesirable losses limit the photoanode thickness and maximum conversion efficiency. Nanowire arrays are promising architectures that have improved electron transport and charge injection due to an electric field. However, DSSC devices based on nanowire-based photoanodes thus far have not been able to take full advantage of the benefits that nanowires offer to electron transport, short circuit current, and open circuit voltage. The objective of this proposal is to develop a model that simulates the performance of nanowire-based DSSCs so that field-assisted charge transport effects within these devices can be understood and used more effectively. The proposed work will focus on combining a charge transport model which accounts for the interfacial electric field with experimental studies to validate the transport dynamics and conversion efficiencies calculated for nanowire-based DSSCs. The anodic-alumina-oxide templating approach used to fabricate the semiconductor oxide nanowires takes advantage of the great flexibility in preparing nanowires with different types of materials, aspect ratios, and spacing. This flexibility allows the systematic study of the effect of field-assisted electron transport on DSSC efficiency. The developed model can be used to determine the fabrication parameters (i.e. nanowire diameter, shell thickness, length, and array density) required to maximize efficiency. These results may also provide new insight into the controlling key reactions or processes in charge transport for DSSCs.Broader ImpactsBeyond photovoltaic applications, the development of nanowire arrays is important to electronic, optoelectronic, environmental, and biomedical applications. The proposed education and outreach activities leverage existing successful programs at the University of Florida (UF). An engineering course sequence in nanotechnology developed through previous a NSF CCLI (Course, Curriculum, and Laboratory Improvement) grant at UF will be enhanced to include solar photovoltaics. Opportunities for undergraduates to participate in the proposed research will be provided through the UF University Scholars Program. Students from under-represented groups will be mentored UF University Minority Mentoring Program through interactions with the PI in the context of the proposed research. Short courses for school teachers on renewable energy and nanomaterials will be offered through the UF Teachers as Scholars Program. High school students will be recruited for summer experiences through the UF Student Science Training Program.