AC Electroluminescence: Optimisation of Phosphors

该项目旨在扩大交流电致发光(ACEL)荧光粉的性能，使其适用于广泛的显示应用。目前，最好的ACEL荧光粉可以在弱光下以合理的亮度制成工作寿命在2000-3000小时左右的器件。以及我们的合作伙伴公司(Pelikon和柯达英国有限公司)我们将调查它们退化的原因(两种都是有涂层的Ar未涂层的荧光粉)，以便充分了解限制其寿命和亮度的因素。这项研究是及时的，因为：完成这项工作所需的一些技术只有在过去5年左右的时间里才对非专家可用。例如，使用RARR显微镜，可以在各种不同的化学环境下，在各种工作条件下检查透明涂层和荧光粉表面之间的界面。使用格林威治大学荧光粉与显示材料中心开发的用于沉淀荧光粉前体粉末的新溶液方法(均匀沉淀法)(同样是在最近5年，因此适时)，因此我们将合成具有更高亮度水平和更长寿命的新ACEL荧光粉。这将通过将通过了解当前最先进的技术而获得的知识在有源发光中心的浓度和分布方面的变化纳入到荧光粉设计中来实现。通过我们从溶液中沉淀的新方法，可以精确控制这些中心的数量和分布。我们还将利用我们对涂层在商业荧光粉中的作用的理解，开发包覆粉末的方法，以进一步延长其使用寿命。将使用聚合物载体来控制颗粒的大小和形态。柯达英国有限公司的实验室将在格林威治开发的新合成技术用于工业生产。我们将与柯达英国有限公司合作，将格林威治大学开发的技术转移到他们的工厂工业生产中。

This project is aimed at extending the performance of AC electroluminescent (ACEL) phosphor powders for a wide range of display applications.Currently the best ACEL phosphor powders can be made into devices that have working lives around 2000-3000 hours at reasonable brightness in subdued lighting. Along with our partner companies (Pelikon and Kodak UK Ltd.) we will investigate the reasons for their degradation (both coated ar uncoated phosphors) so that a full understanding of the factors limiting their lifetimes and brightness can be understood. This study is timely because: some of the techniques necessary to do this work have only become available to the non-specialist in the last 5 years or so. For instance, using Rarr microscopy, it will be possible to examine the interfaces between the transparent coatings and the phosphor surfaces in individual particles under a variety of working conditions in a range of different chemical environments.Using new solution methods for precipitating phosphor precursor powders (homogeneous precipitation methodology) developed in the Centre for Phosphors and Display Materials at the University of Greenwich (again in the last 5 years, hence timely), so we will synthesise new ACEL phosphor powders that have improved brightness levels and longer lifetimes. This will be achieved by incorporating into the phosphor design changes both in concentration and distribution of active light-emitting centres from knowledge gained through understanding the current state-of-the-art. Fine control the number and distribution of these centres is possible from our new methods of precipitation from solution. We will also develop methods of coating the powders to further extend their lifetimes making use of our understanding of the role of the coating in commercial phosphors. Polymeric supports will be used to control particle size and morphology. The new synthetic technology developed at Greenwich will be scaled up for industrial production the laboratories of Kodak UK Ltd. We will work with Kodak UK Ltd. to transfer the technology developed at the University of Greenwich to their plant industrial production.