Tailoring Transport in Transparent and Conducting Non-conjugated Polymers for Next-Generation Materials in Organic Photovoltaic Devices

PI：Boudouris，Bryan建议编号：1336731机构：普渡大学标题：为有机光伏器件中的下一代材料量身定做透明和导电非共轭聚合物的运输有机光伏(OPV)电池记录的器件效率由于材料设计的突破而开始与许多无机光伏系统相媲美；因此，它们是可持续能源生产的潜在来源。然而，许多开创性的研究都集中在设计用于OPV设备半导体层的圆周率共轭、光吸收的大分子。在用于在OPV设备的电极-有机界面提取电荷的新聚合物材料领域取得的成功较少，尽管内在需要有效地从太阳能电池中去除光生电荷。因此，迫切需要开发和了解新型材料中的基本电荷传输，这些材料具有高度透明、在环境条件下稳定并且能够快速传输电荷的能力。在这里，PI引入了一种很有前途的新型导电聚合物，其中稳定的自由基团悬挂在大分子链的每个重复单元上，其聚合物主干完全由脂肪族碳-碳键组成；这些材料被称为自由基聚合物。除了提供一种电荷传导方法外，自由基聚合物还具有传统上与普通脂肪族聚合物(例如聚苯乙烯)相关的优点，因为它们：1)可以由容易合成的单体生成，2)它们的聚合通过受控机制(例如，受控自由基聚合)和大规模发生，以及3)容易从溶液或熔体加工。因此，预计该项目将能够产生透明的导电聚合物薄膜，与传统的OPV电荷收集层[例如聚(3，4-乙烯二氧基噻吩聚(PEDOT：PSS)]相比，具有明显的合成、加工和稳定性优势)，同时仍然保持高的电荷转移速率。自由基聚合物的分子结构与其固态光电性能之间的相互作用对于基本结构-性质关系和它们在OPV器件中的性能都是重要的。破译这些相互作用将需要聚合物合成、结构表征和电子测试的组合。这些技术的应用将导致：1)合成新的空穴导电和电子导电非共轭聚合物，2)描述自由基聚合物中的电荷传输，从而改善这些功能大分子的电导值，以及3)这些材料在OPV设备中的使用，从而可以找到一种环境稳定、低成本的替代现有电荷收集层的方法。因此，研究目标的完成将提供基本的科学认识，为有机电子领域的聚合物开发和界面改性奠定基础，对有机光伏和可持续能源领域产生深远影响。这可能会导致高性能的OPV设备，这将有助于解决当前全球能源格局中的不确定性。此外，关于新型固态聚合物导体中电荷传输关系的基本发现将有可能扩展到目前由共轭材料主导的其他有机电子学领域。除了提供对自由基聚合物导体的具体物理理解外，该项目还将通过实验室和推广活动帮助研究生、本科生和高中生的教学和职业发展。例如，它将通过支持布杜里斯创建的普渡项目种子高中研究经验，增加传统上代表性不足的群体在科学和工程领域的参与。将化学、聚合物科学、化学工程和电气工程学科联系起来，将为参与该项目的研究生、本科生和高中生提供一个独特的机会，从事与能源相关的跨学科研究，使他们为未来在学术界和工业界的努力做好充分准备。研究和教育活动之间的这种协同关系将在产生高影响力的科学成果、产生变革性技术以及激励下一代可持续能源科学家和工程师方面发挥重要作用。

PI: Boudouris, BryanProposal Number: 1336731Institution: Purdue UniversityTitle: Tailoring Transport in Transparent and Conducting Non-conjugated Polymers for Next-Generation Materials in Organic Photovoltaic DevicesOrganic photovoltaic (OPV) cells are recording device efficiencies that are beginning to rival many inorganic photovoltaic systems due to breakthroughs in the design of materials; as such, they present themselves as potential sources of sustainable energy generation. However, much of the groundbreaking research has focused on the design of pi-conjugated, light-absorbing macromolecules for use in the semiconducting layers of the OPV devices. Less success has been had in the realm of new polymeric materials for charge extraction at the electrode-organic interfaces of OPV devices despite the inherent need to remove the photogenerated charges from the solar cell efficiently. Therefore, there exists a critical need to develop and understand the fundamental charge transport in novel materials that are highly transparent, stable in ambient conditions, and that have the ability to transport charges in a rapid manner. Here, the PI introduces a promising new class of conducting polymers where a stable radical group is pendant on each repeat unit of a macromolecular chain whose polymer backbone is composed entirely of aliphatic carbon-carbon bonds; these materials are known as radical polymers. In addition to providing a method by which to conduct charge, radical polymers have the advantages traditionally associated with common aliphatic polymers (e.g., polystyrene) in that they: 1) can be generated from easily-synthesized monomers, 2) have their polymerizations occur through controlled mechanisms (e.g., controlled radical polymerizations) and on large scales, and 3) are processed readily either from solution or from the melt. Therefore, it is anticipated that the project will be able to generate transparent, conducting polymer thin films that have distinct synthetic, processing, and stability advantages over traditional OPV charge-collecting layers [e.g., poly(3,4-ethylene dioxythiophene)-poly(styrene sulfonate) (PEDOT:PSS)] while still retaining high charge transfer rates.The interplay between the molecular architectures of radical polymers and their solid state optoelectronic properties is important both in terms of fundamental structure-property relationships and for their performance in OPV devices. Deciphering these interactions will require a combination of polymer synthesis, structural characterization, and electronic testing. Implementation of these skills will result in: 1) the synthesis of new hole-conducting and electron-conducting non-conjugated polymers, 2) a description of charge transport in radical polymers such that improvement in the conductivity values of these functional macromolecules can occur, and 3) the utilization of these materials in OPV devices such that an environmentally-stable, low-cost alternative to existing charge collecting layers can be found. As such, completion of the research objectives will provide the fundamental scientific understanding to lay the foundation for a new area of polymer development and interfacial modifications in organic electronics with a deep impact in the organic photovoltaics and sustainable energy fields. This could lead to high-performance OPV devices that will help address current uncertainty in the global energy landscape. Furthermore, the basic discoveries regarding charge transport relationships in a new class of solid state polymeric conductors will have the potential to spread to other realms of organic electronics currently dominated by the conjugated materials.In addition to providing a concrete physical understanding of radical polymer conductors, this project will aid in the teaching and career development of graduate, undergraduate, and high school students through laboratory and outreach activities. For example, it will increase the participation of traditionally underrepresented groups in science and engineering through support of the Boudouris-founded Purdue Project SEED high school research experience. Bridging the disciplines of chemistry, polymer science, chemical engineering, and electrical engineering will afford the graduate, undergraduate, and high school students associated with this project a unique opportunity to engage in interdisciplinary, energy-related research that will have them well-prepared for future endeavors in academic and industrial circles. This synergistic relationship between research and educational activities will be of prime import in producing high impact scientific results, generating transformative technologies, and inspiring the next generation of sustainable energy scientists and engineers.