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

有机半导体器件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，代表一种设备的良好材料特性可能对另一种设备的效率非常有害。分子间π - π相互作用就是一个很好的例子：在有机发光器件中，光致发光被这些吸引力猝灭，器件效率急剧降低；在有机场效应晶体管（ofet）中，希望在整个体中促进pi-pi相互作用，以便最大限度地提高电荷迁移率。在本提案中，我们的目标是制备有机光伏（OPV）器件和ofet材料。这项工作的新颖性源于最近的结果，在这些结果中，我们证明了溶液中具有构象自由的高可溶性材料能够在固态中自组装，从而获得高度平面和共轭结构。这种平面度水平，使pi-pi相互作用的可能性最大化，以前只在具有固有溶解度问题的阶梯或带状结构中实现过。在我们的系统中，可以通过使用弱的非共价相互作用来实现远距离平面性；迄今为止，这种方法尚未得到充分考虑，因此有待加以利用。

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.