3D-Localisation - Three Dimensionally Defined Non-Fullerene Acceptors

太阳光提供了一种基本上无限的能量来源。将其转化为电能、热能或化学能是应对能源危机和减少人类活动引起的气候变化影响的最有吸引力和最有效的方法之一。有机太阳能电池是一种新兴技术，可以帮助过渡到可再生经济。它们是轻质、灵活的器件，利用容易获得的有机分子，并且可以通过节能、非热方法进行处理，这与传统的硅器件不同。这些器件的发展依赖于富勒烯作为电子受体材料。富勒烯是碳的分子形式，具有球形、足球状的几何形状，其引起电子在整个分子表面上的离域。这种结构使富勒烯具有各种独特的性质，它们可以可逆地接受多达六个电子，并且可以在三维空间中有效地传输电荷。然而，现在公认的是，使用富勒烯对有机太阳能电池的性能有严格的限制。富勒烯对阳光的吸收很差，并且它们在操作时参与对设备有破坏性的过程。除此之外，它们的生产和购买都很昂贵，并且在任何程度的控制下进行化学改性都极具挑战性。这意味着它们的光学和电子特性不能容易地针对太阳能电池或任何其他特定应用进行调整。最终，富勒烯的使用是不可持续的，因此，如果这些绿色能源技术要实现其全部潜力，就迫切需要新的非富勒烯受体。该项目全面考虑了富勒烯的有利和不利特性，并将使用这种方法来生产一种全新的非富勒烯受体。这些将对可再生能源的供应产生巨大影响。这种方法有两个关键方面：1）使用三维分子结构作为中心支架。2）通过将杂环侧基连接到这些支架上，太阳能吸收率将最大化，这些新分子的电化学和形态学特性将以简单的方式得到控制。这代表了有用的非富勒烯受体开发的一个阶段性变化。将生产用于能量转换技术的新一代分子材料，并将建立一般和任何应用程序实现真正富勒烯样行为的设计规则。与现有的许多有机电子材料的工作相比，它集中在平面杂环片段组成的分子和聚合物上，探索三维化学空间是这里提出的工作的关键。这大大增加了我们方法的新奇。

Sunlight presents an essentially infinite source of energy. Converting it into electricity, heat, or chemical energy is among the most appealing and effective approaches to tackling the energy crisis and reducing the impact of human activity induced climate change. Organic solar cells are one emerging technology that can aid in the transition to a renewable economy. They are lightweight, flexible devices which utilise readily available organic molecules and can be processed by energy-efficient, non-thermal methods unlike traditional silicon devices. The development of these devices has relied upon fullerenes as electron acceptor materials.Fullerenes are molecular forms of carbon with a spherical, soccer ball-like geometry which gives rise to delocalisation of electrons across the entire surface of the molecule. This structure attributes fullerene with a variety of unique properties, they can reversibly accept up to six electrons and can transport charges efficiently in three dimensions. However, it is now well-established that using fullerenes places strict limitations on organic solar cell performance. Fullerenes absorb sunlight only poorly and they participate in processes which are destructive to the device while under operation. Compounding this, they are expensive to produce and purchase, and are extremely challenging to chemically modify with any degree of control. This means that their optical and electronic properties cannot be easily tuned for solar cells or any other specific application. Ultimately, the use of fullerenes is non-sustainable therefore new non-fullerene acceptors are urgently required if these green energy technologies are to realise their full potential.This project takes a holistic view of the beneficial and detrimental properties of fullerenes and will use this approach to produce a completely new class of non-fullerene acceptors. These will serve to impact hugely on the delivery of renewable energy sources. There are two key facets to this approach:1) The use of three-dimensional molecular structures as a central scaffold. These will facilitate electronic delocalisation in three dimensions.2) By attaching selected heterocyclic side groups to these scaffolds, solar absorbance will be maximised, and the electrochemical and morphological properties of these new molecules will be controlled in a facile manner.This represents a step-change in the development of useful non-fullerene acceptors. A new generation of molecular materials for use in energy conversion technologies will be produced, and design rules for attaining truly fullerene-like behaviour in general, and for any application, will be established. In contrast with much of the existing work on organic electronic materials, which focusses upon molecules and polymers composed of planar heterocyclic fragments, exploring chemical space in three dimensions is key to the work proposed here. This adds significantly to the novelty of our approach.