Design, synthesis, and properties of self-organizing dyes

我们的研究小组开发基于自组织染料和其他化合物（例如液晶）的新材料，以及基于聚合物和纳米颗粒及其复合材料的纳米结构材料。天然和合成染料在我们的环境中无处不在，并且对特定技术具有改进性能的新染料的需求不断增加。在这个建议中，我们将开发新的有机染料的设计标准，（i）自组织成柱状堆栈和（ii）形成一个分子厚的膜（单层）的定义结构。所有提出的项目都强调有机电子潜在应用的关键特性，尽管我们知道这一领域的发展具有多种应用，从着色剂和荧光探针到基于分散液晶的高压润滑剂。* 已经确定的是，芳香族染料的柱状叠层用作各向异性有机半导体，其已经实现了上级目前使用的有机半导体的电荷传输性质。然而，在电子器件中利用柱状相作为有机半导体已经停滞，因为它们的加工对于主要通过印刷技术制造的工业目标低成本器件来说太复杂。我们确定了横向侧链的附着，这是几乎所有已知柱状相的共同设计概念，是其作为商业器件应用的有机半导体的主要缺陷的根本原因。第一个项目的主要目标是开发基于不含侧链的柱状相的有机半导体。具体来说，我们将针对本体异质结有机太阳能电池中有机半导体所需的材料特性，因为我们相信染料的柱状相由于其自组织特性而具有一些优于传统有机半导体的独特优势，这些特性应有助于形成所需的纳米结构。太阳能电池的制造和测试将与学术和工业合作伙伴合作进行。电极之间分子的垂直排列以形成柱状结构对于具有半导体性质的有机器件是必不可少的，因为电荷传导仅沿着柱状叠层高。然而，有机发光和光伏器件所必需的这种包装图案特别难以实现。我们的第二组建议的项目直接解决这个问题，通过制备不溶性，单分子染料膜，表现出平的染料分子相对于基板的取向。预期这些膜用作目前不能在衬底上垂直对准的许多柱状相的第一垂直对准层。所提出的方法进一步推进了我们最近开发的关于薄膜中染料分子排列及其交联成热稳定和化学稳定薄膜的技术。然而，具有平贴取向的交联染料的应用不限于它们用作柱状相的取向层。我们的长期目标包括将这些膜用作电极表面的化学和电子改性的坚固涂层，以及基于这种对齐和交联方法的染料的2维共轭膜和3维共轭体材料的开发。特别是修饰电极表面的表征，无机电极材料和有机半导体之间的界面优化的重要选择，将需要与专家组的合作，并提供极好的机会，以加强HQP的培训。

Our research group develops new materials based on self-organizing dyes and other compounds (e.g. liquid crystals), and nanostructured materials based on polymers and nanoparticles as well as their composites. Natural and synthetic dyes are ubiquitous in our environment and new dyes with improved properties for specific technologies are constantly in demand. In this proposal we shall develop new design criteria for organic dyes that (i) self-organize into columnar stacks and (ii) form one molecule thick films (mono-layers) of defined structure. All proposed projects emphasize properties that are critical for potential applications in organic electronics, though we are aware that developments in this area have a diverse range of applications from colorants and fluorescent probes to discotic liquid crystal based high pressure lubricants. *It is well established that columnar stacks of aromatic dyes function as anisotropic organic semiconductors that have achieved charge transport properties superior to presently used organic semiconductors. However, the utilization of columnar phases as organic semiconductors in electronic devices has stalled because their processing is too complex for industrially targeted low cost devices that are mainly manufactured by printing technologies. We identified the attachment of lateral side-chains, a design concept common to almost all known columnar phases, as the root cause for their main deficiencies as organic semiconductors for commercial device applications.*The main objective of the first project is the development of organic semiconductors based on columnar phases that do not contain lateral side-chains. Specifically, we will target materials properties required for organic semiconductors in bulk-heterojunction organic solar cells as we believe columnar phases of dyes have some unique advantages over conventional organic semiconductors due to their self-organizing properties that should aid the formation of the required nanostructures. Fabrication and testing of solar cells will be conducted in collaboration with both academic and industrial partners.*The vertical alignment of molecules between the electrodes to form columnar structures is essential for organic devices with semiconductor properties since charge conduction is only high along the columnar stacks. Yet this packing motif, which is necessary for organic light emitting and photovoltaic devices, is particularly difficult to achieve. Our second set of proposed projects directly addresses this problem through the preparation of insoluble, unimolecular dye films that exhibit flat-on orientations of the dye molecules with regard to the substrate. These films are expected to function as the first vertical alignment layer for the many columnar phases that presently cannot be aligned vertically on substrates. The proposed approaches further advance technology we recently developed on the alignment of dye molecules in thin films and their cross-linking to thermally and chemically robust films.*Applications of cross-linked dyes with flat-on orientation, however, are not limited to their use as alignment layer for columnar phases. Our long term objectives include the application of these films as robust coatings for chemical and electronic modification of electrode surfaces as well as the development of 2-dimensionally conjugated films and 3-dimensionally conjugated bulk materials of dyes based on this alignment and cross-linking methodology. Especially the characterization of modified electrode surfaces, an important option for the optimization of interfaces between inorganic electrode materials and organic semiconductors, will require collaborations with expert groups and afford excellent opportunities to enhance the training of HQP.