International Research Fellowship Program: Design, Synthesis and Characterization of Novel Conduction Polymers for Dye-sensitized Solar Cells

国际研究奖学金计划使美国科学家和工程师能够在国外进行9至24个月的研究。该计划的奖项提供了联合研究的机会，并利用国外独特或互补的设施、专业知识和实验条件。该奖项将支持瑞安·C·怀特博士与巴西坎皮纳斯大学的马尔科-奥雷里奥·德·保利博士合作的为期22个月的研究奖学金。该项目得到了国际科学与工程办公室(OISE)美洲项目的支持。随着对可再生能源需求的增长，染料敏化太阳能电池(DSC)正在成为60多年前开发和商业化的传统硅电池的可行替代品。最广为人知的是Gratzel电池，它的总效率可以达到10%。在这种电池的生产中取得的一个主要进展是加入了高比表面积的介孔金属氧化物材料。这增加了特定区域中与表面接触的染料分子的数量。虽然这些类型的细胞已经在商业上证明了这些类型的细胞的潜在生存能力，但由于所需的反应性电解液以及昂贵的染料分子前体，它们的制造被证明是困难和昂贵的。在de Paoli博士的实验室和其他实验室中，共轭聚合物材料被用作光活性染料和电解液。这些聚合物在成本和耐用性方面比小分子有一定的优势，同时表现出与Gratzel细胞染料分子相似的吸收特性。到目前为止，含有聚合染料的DSSC的转换效率相对较低。本项目的目标是开发具有更高效电荷传输性能的聚合物染料材料，并制备更高效的直接序列存储器件。通过将共轭聚合物薄膜共价连接到无机衬底上，获得了更好的轨道重叠，并增加了电子注入到电路中的速度。染料单体和连接剂的同一性都可以改变，以优化注射工艺。为了定量研究电子注入性能，合成了不同无机纳米粒子-连接剂-染料组合的模型化合物。这是通过用能够锚定在金属氧化物纳米颗粒表面的羧基或膦酸基来修饰共轭单体分子如噻吩来实现的。这些化合物的电子转移速率可以直接用时间分辨激光、闪光、吸收和荧光技术来研究。为了将聚合物染料连接到无机层，共轭的染料单体通过锚定基团连接到无机表面，并通过化学和电化学方法聚合。在De Paoli博士的实验室里，用电化学仪器分析了这些新型的DSSC的光伏响应和效率。

0601913WhiteThe International Research Fellowship Program enables U.S. scientists and engineers to conduct nine to twenty-four months of research abroad. The program's awards provide opportunities for joint research, and the use of unique or complementary facilities, expertise and experimental conditions abroad.This award will support a twenty-two-month research fellowship by Dr. Ryan C. White to work with Dr. Marco-Aurelio De Paoli at the University of Campinas in Brazil. Support for this project comes from the Office of International Science and Engineering's (OISE) Americas Program.As the need for renewable energy resources grows, dye-sensitized solar cells (DSSCs) are emerging as a viable alternative to the traditional silicon cells developed and commercialized over 60 years ago. The most well known DSSC is the Gratzel cell which can reach an overall efficiency of ~10%. One major advance made in the production of this cell is the incorporation of high surface area mesoporous metal oxide materials. This increases the amount of dye molecules in contact the surface in for a given area. While these types of cells have proved the potential viability of these types of cells commercially, their fabrication proves difficult and expensive due to the reactive electrolyte needed, as well as expensive dye molecule precursors. In the Dr. De Paoli's laboratory, and others, conjugated polymeric materials have been used as the both photoactive dyes and electrolytes. These polymers have definite advantages over small molecules in cost and durability, while showing similar absorption characteristics of Gratzel cell dye molecules. To date the DSSC's containing polymeric dyes have had relatively low conversion efficiencies. The goal of this project is to develop polymeric dye materials with more efficient charge transport properties and to fabricate more efficient DSSCs. By covalently attaching the conjugated polymer film to the inorganic substrate, better orbital overlap is achieved and the rate of electron injection into the electrical circuit is increased. The identity of both the dye monomer and linker can be changed to optimize the injection process. To quantitatively study the electron injection properties, model compounds are synthesized of different inorganic nanoparticle-linker-dye combinations. This is accomplished by modifying conjugated monomers molecules such as thiophene with carboxylic or phosphonic acid groups which can anchor onto the metal oxide nanoparticle surface. Electron transfer rates of these compounds can be studied directly by time resolved laser flash photolysis absorbance and fluorescence techniques. To attach the polymeric dye to the inorganic layer, the conjugated dye monomers are attached to inorganic surfaces via anchoring groups and polymerized by chemical and electrochemical means. The photovoltaic responses and efficiencies of these novel types of DSSC's are analyzed by electrochemical instrumentation in Dr. De Paoli's laboratory.