Multilayer photopatterned dendrimer LEDs for colour displays

该提案的目的是基于最近在称为共轭树枝状聚合物的高度支化分子方面的进展，开发用于显示器的新发光材料。共轭树枝状聚合物是一类令人兴奋的材料，它联合收割机了分子和聚合物材料的优点，并且根据本文提出的工作，可以用于制造低成本的彩色显示器。它们具有类似于分子材料的明确结构，但具有通常与聚合物相关的溶液加工性的关键优势。树枝状聚合物由核心、树枝状分子和表面基团组成，这些组分中的每一种的选择都为优化材料的光电性能提供了巨大的控制。我们已经发现，当小的磷光铱络合物被封装到一个大的分支分子（树枝状聚合物），可以获得高效率，在更简单的设备结构比那些用于小的磷光分子。我们已经展示了红色绿色和蓝色树枝状聚合物发光二极管。然而，所有这些器件都是单色的，并且层的可溶性意味着我们只能使用两层器件。我们现在希望通过开发用于使树枝状聚合物图案化以形成全色像素化显示器的方法来克服这些限制。树枝状聚合物将通过引入能够交联的表面基团而在固态下图案化。这将允许彩色显示器的精确图案化。此外，这些交联材料将使多层器件能够由溶液制成，提高效率，并提供研究器件物理的新方法。

The purpose of this proposal is to develop new light-emitting materials for displays, based on recent progress in highly branched molecules called conjugated dendrimers. Conjugated dendrimers are an exciting class of materials that combine the advantages of molecular and polymeric materials and following the work proposed here could be used to make low cost colour displays. They have well defined structures akin to molecular materials, but with the key advantage of having the solution processibility normally associated with polymers. Dendrimers consist of a core, dendrons, and surface groups and the choice of each of these components gives enormous control for optimising the material's opto-electronic properties. We have discovered that when small phosphorescent iridium complexes are encapsulated into a large branched molecule (dendrimer) high efficiencies can be obtained in much simpler device structures than those used for small phosphorescent molecules. We have demonstrated red green and blue dendrimer light-emitting diodes. However, all these devices have been monochrome and the soluble nature of the layers has meant that we have only been able to use two layer devices. We now wish to overcome these limitations by developing methods for photopatterning dendrimers to form a full colour pixellated display. The dendrimers will be patterned in the solid state by incorporating surface groups capable of being cross-linked. This will allow precise patterning of colour displays. In addition these cross-linked materials will enable multilayer devices to be made from solution, giving improvements in efficiency, and providing new ways of studying device physics.