Resolution of Important Remaining Puzzles in Conjugated Polymer Photophysics

技术：该项目旨在提供对用于光电子应用的共轭聚合物中的光物理的详细了解。对电致发光聚合物的溶液和薄膜进行了瞬时吸收和延迟发光实验，以解决薄膜中荧光量子产率下降的根本原因，以及有机发光二极管中载流子复合形成单重态的分支率和磁场效应的来源。在与利用共轭聚合物制造太阳能电池相关的施主-受主混合物中，通过延迟场收集实验来量化电荷的光生效率和瞬时吸收，以确定能量转移是否在有机光伏中起重要作用。非技术性：该研究对基于可加工的共轭聚合物材料的太阳能电池、光泵薄膜激光器、照明、显示器件和自旋电子技术的材料和器件结构的设计具有重要意义。参与研究的研究生和本科生在凝聚态物理、光学、材料科学、分析化学和设备工程等多个领域获得跨学科培训。与当地一名高中科学教师合作，为中学生开发了演示共轭聚合物如何改变颜色并实现太阳能电池中的光检测的动手教学模块，并在互联网上传播

Technical: This project is designed to provide a detailed understanding of photophysics in conjugated polymers used for optoelectronic applications. Transient absorption and delayed luminescence experiments are performed on solutions and films of electroluminescent polymers to address the root cause of the decrease in fluorescence quantum yield in films, the branching ratio for recombination of charge carriers to form singlet states and the origin of magnetic field effects in organic light-emitting diodes. In donor-acceptor blends relevant to fabrication of solar cells from conjugated polymers, time-delayed field collection experiments to quantify charge photogeneration efficiency and transient absorption to ascertain whether energy transfer plays an important role in organic photovoltaics.Nontechnical: The research has implications for the design of materials and device structures for solar cells, optically pumped film lasers, lighting, display devices and spintronic technologies based on processable conjugated polymer materials. Graduate and undergraduate students participating in the research acquire interdisciplinary training in areas as diverse as condensed matter physics, optics, materials science, analytical chemistry and device engineering. Hands-on educational modules demonstrating how conjugated polymers can change color and enable light detection as in solar cells are developed for middle and secondary school students in collaboration with a local high school science teacher and disseminated on the Internet