Self-assembling conjugated macromolecules for organic field effect transistors and solar cells

有机半导体器件的理想材料的设计和构造需要仔细考虑一系列物理性质。在某些情况下，对于一种类型的器件来说，代表良好材料特性的东西可能对另一种类型的器件的效率非常有害。分子间π-π相互作用是一个很好的例子：在有机发光器件中，光致发光被这些吸引力淬灭，器件效率显著降低;在有机场效应晶体管（OFFET）中，希望促进整个体的π-π相互作用，使得电荷迁移率可以最大化。在这项提案中，我们的目标是制备用于有机光伏（OPV）器件和OFFEs的材料。这项工作的新奇源于最近的结果，在这些结果中，我们证明了在溶液中具有构象自由度的高度可溶性材料能够在固态下自组装，以获得高度平面和共轭的结构。这种使π-π相互作用的可能性最大化的平面性水平以前仅用具有固有溶解度问题的梯形或带状结构实现。在我们的系统中，长程平面性可以通过使用弱的非共价相互作用来实现;到目前为止，这种方法还没有得到重要的考虑，因此等待被利用。

The design and construction of an ideal material for organic semiconductor devices requires the careful consideration of a range of physical properties. In some cases, what would represent good materials characteristics for one type of device may be highly detrimental to the efficiency of another. Intermolecular pi-pi interactions symbolise one good example: in organic light emitting devices, photoluminescence is quenched by these attractions and the device efficiency is reduced dramatically; in organic field effect transistors (OFETs), it is desirable to promote pi-pi interactions throughout the bulk, so that charge mobility can be maximised. In this proposal, we aim to prepare materials for organic photovoltaic (OPV) devices and OFETs. The novelty in this work originates from very recent results, in which we demonstrate that highly soluble materials with conformational freedom in solution are able to self-assemble in the solid state to give highly planar and conjugated structures. Such levels of planarity, which maximise the possibility of pi-pi interactions, have only been achieved previously with ladder or ribbon type structures which possess inherent solubility problems. In our systems, long range planarity can be achieved through the use of weak, non-covalent interactions; to date, this approach has not been given significant consideration and is therefore waiting to be exploited.