Resolution of Important Remaining Puzzles in Conjugated Polymer Photophysics

技术：本项目旨在提供用于光电应用的共轭聚合物的电子物理学的详细了解。通过对电致发光聚合物溶液和薄膜的瞬态吸收和延迟发光实验，研究了有机电致发光聚合物薄膜中荧光量子产率下降的根本原因、载流子复合形成单重态的分支比以及有机电致发光二极管中磁场效应的起源。在与由共轭聚合物制造太阳能电池相关的供体-受体共混物中，进行延时场收集实验，以量化电荷光生效率和瞬态吸收，从而确定能量转移是否在有机光致发光中起重要作用。这项研究对太阳能电池、光泵薄膜激光器、照明、基于可加工共轭聚合物材料的显示器件和自旋电子技术。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不同领域获得跨学科培训。与当地高中科学教师合作，为中学生开发了实践教学模块，展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，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