Polymers for Solar Energy Applications: Exploring Charge Carriers with Raman Spectroscopy and Electrochemistry

半导体聚合物在有机光伏、光催化和其他能源应用中非常重要。有机光电器件的稳定性是限制其商业化的一个关键因素，但主要降解机制的结构起源在很大程度上仍然未知。该项目将确定带电聚合物（光伏运行期间的活性物质）中发生的特定结构变化，并结合已知的降解因素（如氧气和水）。反过来，这将使设计新的，更坚固的材料成为可能。确定特定的降解机制不仅有利于有机光伏领域，而且也有利于许多其他应用，这些聚合物被利用：例如显示技术中的发光二极管。为了探索半导体聚合物中的这些降解机制，电化学和拉曼光谱将结合起来，创造出功能强大但很少使用的光谱电化学共振拉曼。该技术不仅对分子结构和构象的微小变化高度敏感，而且可以在多个共存物种的系统中选择性探测单个物种。因此，本项目旨在将这种新的光谱电化学共振拉曼技术应用于一系列共轭聚合物，以确定电子转移过程中特定的结构变化，以阐明其降解机制。这个项目的一个直接成果将是设计规则的创建，以减轻有机光伏材料的降解。因此，该项目与EPSRC的能源主题直接一致，涉及能源应用材料，化学结构和电化学科学的研究领域。

Semiconducting polymers are important in organic photovoltaics, photocatalysis, and other energy applications. The stability of organic photovoltaic devices is a critical factor limiting their commercialisation, but structural origins of the primary degradation mechanisms remain largely unknown. This project will identify specific structural changes that occur in the charged polymers (the active species during photovoltaic operation) in combination with known degradation factors such as oxygen and water. In turn, this will enable the design of new, more robust materials. Identification of specific degradation mechanisms will benefit not just the organic photovoltaic field, but also many other applications where such polymers are utilised: light emitting diodes in display technology, for example. To explore these degradation mechanisms in semiconducting polymers, electrochemistry and Raman spectroscopy will be combined to create the powerful but seldom-used spectroelectrochemical resonance Raman. This technique is not only highly sensitive to small changes in molecular structure and conformation, but also allows the selective probing of a single species in a system with multiple co-existing species. This project therefore aims to apply this novel technique of spectroelectrochemical resonance Raman to a series of conjugated polymers to ascertain specific structural changes during electron transfer, in order to elucidate their degradation mechanisms. A direct outcome of this project will be the creation of design rules to alleviate degradation in organic photovoltaic materials. As such, this project aligns directly with EPSRC's Energy theme, tackling the research areas of Materials for Energy Applications, Chemical Structure, and Electrochemical Sciences.