Organic Materials for Optoelectronic Technologies

有机半导体材料在一系列新兴技术中产生了广泛的影响。最近在材料合成和器件工程方面的努力已经达到了制造有机发光二极管、薄膜晶体管、固体激光器、太阳能电池和光电探测器的顶峰。甚至有人猜测，将创造出用于计算目的的全有机电路。所有这些功能的基础是固体中有机生色团之间的空间关系，以及这个参数控制不同亚基之间的电子耦合的方式。此外，固体中的有序度决定了小分子材料形成稳定的无定形薄膜的能力，以及它们可能包含在器件结构中。这项提议在明年有两个目标。首先是开发必要的方法来制备定义明确的分子，这些分子具有几何属性，可以产生非晶态材料。这种类型的材料可以比聚合物同类材料得到更大程度的净化，并在小浓度污染物不成比例地影响电荷迁移的设备中提供优势。第二个目标是用上述化合物制作器件，并利用所得到的性能曲线来探索分子形状对块体电荷传输能力的影响。在授权期内的具体目标是：(1)合成结构精确的具有四面体几何构型的共轭有机分子。有趣的是研究拓扑学如何转化为整体形态。将进行光谱研究，以更好地了解生色团含量较高的有机玻璃中存在的环境的类型和可变性。这将通过将溶致变色染料加入到有机无定形薄膜中并通过测量由此产生的光学性质来实现。这里的最终目标是制定指导方针，允许调整无序系综中生色团的协作性，并更好地理解非晶态有机固体中可能存在的局部有序。(2)使用上述材料制造发光二极管。对器件性能的分析将有助于深入了解分子形状如何影响重要的整体性质，如导电性和电致发光量子产率。

9985632BazanOrganic semiconducting materials are making a widespread impact in a range of emerging technologies. Recent efforts in materials synthesis, in conjunction with device engineering, has culminated in the fabrication of organic-based light emitting diodes, thin film transistors, solid state lasers, solar cells and photodetectors. There is even speculation about the creation of all-organic circuitry for computing purposes. Underlying all these functions is the spatial relationship between organic chromophores in the solid and the manner by which this parameter controls the electronic coupling between different subunits. Additionally, the level of order in the solid determines the ability of small molecule materials to form stable amorphous films and their potential inclusion into device structures.The goals of this proposal over the next year are twofold. The first is to develop the necessary methodology to prepare well-defined molecules with geometrical attributes that yield amorphous materials. Materials of this type can be purified to a greater extent than polymer counterparts and offer advantages in devices where a small concentration of contaminants disproportionately affects charge migration. The second aim is to fabricate devices with the above compounds and to use the resulting performance profiles to probe the effect of molecular shape on the charge transport ability of the bulk. The specific objectives during the grant period are:(1) The synthesis of structurally-precise conjugated organic molecules with tetrahedral geometries. Of interest will be to examine how topology translates into bulk morphology. Spectroscopic studies will be executed to understand better the types and variability of environments present in organic glasses with a high chromophore content. This will be achieved by incorporating solvatochromic dyes into organic amorphous films and by measuring the resulting optical properties. The ultimate goal here is to develop guidelines that allow for tuning the cooperativity of chromophores in a disordered ensemble and to develop a better understanding of the local order that may exist in amorphous organic solids.(2) To fabricate light emitting diodes using the above materials. Analysis of device performance will provide useful insight into how molecular shape affects important bulk properties such as conductivity and electroluminescence quantum yield.