NSF-Europe: Materials for Electrochemical Luminescent Devices

这是得克萨斯大学奥斯汀分校和意大利博洛尼亚大学Dipartimento Di Chimica G.Ciamist的研究人员合作的项目。该项目和意大利的合作项目致力于合成和(光谱)电化学表征具有电化学诱导发光的新型化合物。作为研究对象的主要化合物是Ru(联吡啶)(联吡啶)配合物衍生物。与意大利研究小组合作的一个附加价值是，有可能将研究扩展到其他Ru-络合物衍生物，例如使用取代的联吡啶和邻菲咯啉，这可以提供具有更高量子效率和更长工作寿命的材料。利用各种反离子也是有用的，从与ClO4-和BF4-相比具有更高迁移率的OH-，到其大小将有效阻碍离子传输的非常大的离子(例如，对十二烷基苯磺酸盐)。后一种离子的使用有助于阐明离子迁移率的作用以及发光器件的其他电荷注入机制的可能性。分子在溶液中的表征将通过两种不同的电化学发光检测仪器(一种安装PMT摄像头，另一种安装CCD摄像头)和干燥箱来完成，以在受控条件下制备溶液。在对该系统的特性(量子效率、耐用性)进行评估后，这些特性将与标准的发光系统进行比较，以判断这些新分子的相对质量和定量效率。基于这些分子体系制备固态发光器件(OLED)是该项目的主要目标。因此，人们将努力寻找合适的条件，使这些物质能够附着在表面上，主要是氧化铟锡(ITO)，以形成有用的薄层。将使用旋涂、气相沉积和电化学沉积等技术。还将研究材料纯度和结构对产品性能的影响。此外，还将使用扫描探针显微镜来研究这些薄膜。基于音叉的扫描隧道显微镜的初步实验已经证明了能够同时产生分子薄膜的光发射、电流和地形图像。这种新的和信息丰富的技术可以很容易地用于这些新材料的研究。%该项目解决了与具有技术相关性的电子/光子材料相关的基础研究问题。该项目的一个重要特点是非常重视教育，强调研究与教育的结合，以及提供科学和教育益处的国际合作。这种互动的一个重要组成部分将是长时间的学生交流。该NSF项目由材料研究司和国际办公室(西欧)共同资助，作为NSF和欧洲在材料研究方面的合作活动(NSF 02-135)。该项目是与意大利博洛尼亚德格利研究大学合作开展的。

This is a collaborative project between researchers at the University of Texas, Austin and at Dipartimento Di Chimica G. Ciamician, Universita Degli Studi Di Bologna, Italy. This project and its Italian counterpart are focused on the synthesis and (spectro-) electrochemical characterization of new classes of compounds that display electrochemically induced luminescence. The primary compounds that are the object of study are Ru(bipyridine)(terpyridine) complex derivatives. An added value of the collaboration with the research group in Italy is the possibility of extending the study to other Ru-complex derivatives, e.g., using substituted bipyridines and phenanthrolines, which could provide materials with increased quantum efficiencies and improved operating lifetimes. It could also be useful to utilize various counterions ranging from OH- that has higher mobility, compared to ClO4 - and BF4 -, to very big ions whose size will effectively hinder ion transport (e.g., p-dodecylbenzenesulphonate). The use of latter ions could assist in elucidating the role of ion mobility and the possibility of other charge injection mechanisms for the light-emitting devices. Molecular characterization in solution will be done by two different electrochemical luminescence detector instruments (one mounting a PMT camera, the other a CCD camera) and a dry box to prepare the solutions under controlled conditions. After an evaluation of the characteristic properties of the system (quantum efficiency, durability) these will be compared to a 'standard' light emitting system to judge the relative quality and the quantitative efficiency of these new molecules. The preparation of solid-state light emitting devices (OLEDs) based on these molecular systems is a prime target of the project. Therefore, effort will be placed on the search for suitable conditions under which these substances can be attached to a surface, mainly indium tin oxide (ITO), to form useful thin layers. Techniques such as spin coating, vapor deposition, and electrochemical deposition will be used. A study on the effect of material purity and structure on the properties of the products will be also carried out. Additionally, scanning probe microscopy will be employed to investigate these films. Preliminary experiments with a tuning fork-based scanning tunneling microscope have demonstrated the ability to produce simultaneous light emission, current, and topographic images of molecular thin films. This new and information-rich technique can be readily employed in the study of these new materials.%%% The project addresses fundamental research issues associated with electronic/photonic materials having technological relevance. An important feature of the project is the strong emphasis on education, with emphasis on integration of research and education, and an international collaboration providing both scientific and educational benefits. An important component of this interaction will be exchange of students for extended periods of time. This NSF project is co-funded by the Division of Materials Research, and the International Office (Western Europe) as a Cooperative Activity in Materials Research between the NSF and Europe (NSF 02-135). This project is being carried out in collaboration with the Universita Degli Studi Di Bologna, Italy.