Interface Structure and Emission Efficiency of Polymeric Light Emitting Diodes

9303019高这项研究解决了聚合物发光二极管(LED)中的表面和界面现象。其目的是了解电致发光中涉及的电子态以及聚合物/金属界面的电子和化学结构。将使用X射线光电子能谱(XPS)、反向光电子能谱(IPES)、电致发光光谱(ELS)和其他表面敏感探针，对聚苯乙炔PPV与部分金属的界面形成进行协调实验研究。XPS和IPES在同一超高真空(UHV)系统中的组合允许独立和同时探测被占据和未被占据的电子结构。ELS的同时测量有望揭示光发射效率与界面电子结构和化学之间的关系。这项研究有望为聚合物平板显示技术的未来发展提供有用的基础信息。实际感兴趣的参数，如聚合物和金属层的厚度，不同的转化率和不同类型的发光聚合物，以及LED的稳定性将被研究。该项目结合了表面物理和聚合物化学的专业知识，是大学和工业研究科学家的联合努力。该项目的跨学科性质以及学术和行业合作预计将独特地使学生受益，并促进知识从大学向行业的转移。***

9303019 Gao This research addresses surface and interfacial phenomena in polymeric light emitting diodes (LEDs). The objectives are to understand the electronic states involved in electroluminescence and the electronic and chemical structure of polymer/metal interfaces. Coordinated experimental studies of the interface formation of poly(phenylene vinylene)PPV and a selection of metals using x-ray photoemission spectroscopy (XPS), inverse photoemission spectroscopy (IPES), electroluminescence spectroscopy (ELS), and other surface sensitive probes will be conducted. The combination of XPS and IPES in the same ultra-high vacuum (UHV) system allows probing of both occupied and unoccupied electronic structures independently and simultaneously. Concurrent measurement of ELS is expected to reveal relationships between light emission efficiency and interface electronic structure and chemistry. %%% This research is expected to provide fundamental information useful for the future development of polymer based flat panel display technologies. Parameters of practical interest such as the thicknesses of the polymer and metal layers, different degrees of conversion and different types of light emitting polymers, and the stability of the LEDs will be investigated. The project combines expertise in surface physics and polymer chemistry, and is a joint effort between university and industrial research scientists. The interdisciplinary nature of the project and the academic and industrial collaboration is expected to uniquely benefit students and enhance the transfer of knowledge from university to industry. ***