EXPLORER; Excitonic Polymer Organic Devices for Energy

我们在能源研究领域提出了三个富有冒险精神的跨学科项目。在过去的十年里，人们对有机电子领域的兴趣高涨。发光显示器和化学和物理传感器等设备已经在市场上--可能就在你的家里和你的口袋里--而其他设备，如太阳能电池正在快速发展。其动机是降低成本、易于制造、大面积能力以及使用这些新技术可能提高的效率。然而，仍然需要进行更多的研究。这项研究将结合：(I)新材料的合成，(Ii)详细的光谱表征，(Iii)器件制造和性能测量，以及(Iv)理论计算。该小组将研究其性能发生系统变化的材料，目的是在三个方面提高它们的性能。分子内部和分子之间的能量传递是一个中心主题。(I)更高效的显示技术和新型照明。有机发光器件(OLED)使用小分子或聚合物，这些小分子或聚合物由共轭环和π电子组成，将电能转化为可见光。该项目的创新特征是使用了从双重态(即当金属有一个未配对的电子时)发射的分子的金属络合物。这是一个以前从未在有机发光二极管上测试过的想法，如果成功，它可以克服当前技术的一个主要限制。现有的设备使用具有单态或三态的分子，这限制了它们的效率。特别是，我们的战略可能会导致更高效的蓝色排放者。这对于全彩色显示器和在照明应用中产生白光是必不可少的。由于照明占英国能源消耗的20%以上，迫切需要新的高效白光光源。(Ii)提高有机太阳能电池的性能。众所周知，共轭有机分子可以捕捉阳光并将其转化为电能。然而，电力转换效率很低(只有6%左右)，即94%的太阳辐射不会产生电流。我们将探索一条提高这一效率的创新之路。当太阳能电池中的分子吸收阳光时，至关重要的是以一种精确的方式在分子之间传递这种能量，以获得高效的电力输出。一个主要的问题是如何防止带电的分子态重新组合(猝灭)--这是一个不会产生电的过程。我们将探索使用低能三重态来克服这个问题。三重态的优点是它们的寿命更长，因此可以在分子内移动得更远，不太可能重新结合。将开发一种新的设备架构，可以利用三胞胎并更高效地发电。(Iii)减少大气中的二氧化碳。我们都意识到大气中二氧化碳水平不断上升带来的巨大环境问题。我们提出了一种将二氧化碳转化为燃料原料的新方法。原理是这样的：共轭聚合物有效地吸收光，然后将它们的电子转移到纳米颗粒或纳米管。这些电荷将被用来将二氧化碳转化为有用的燃料分子，如甲烷或乙醇(可用于替代石油或煤炭)，而不是产生电流(如太阳能电池)。我们的计划是利用有机金属络合物将二氧化碳捕获到纳米粒子的表面。我们正在与工业合作伙伴联系，他们将提供投入，促进未来开发有希望的成果。

We propose three adventurous, cross-disciplinary projects within the area of energy research. The past decade has seen an upsurge in interest in the field of organic electronics. Devices such as light-emitting displays and chemical and physical sensors are already on the market - and probably in your home and in your pocket - while others, such as solar cells are developing fast. The motivation is the reduced cost, ease of manufacture, large-area capability and the enhanced efficiency which is possible using these new technologies. However, a lot more research is still needed. This study will unite: (i) the synthesis of new materials, (ii) detailed spectroscopic characterisation (iii) device fabrication and measurements of performance, and (iv) theoretical calculations. The team will study materials whose properties are systematically changed with the aim of enhancing their performance in three areas. Energy transfer within and between molecules is a central theme.(i) More efficient display technologies and new types of lighting. Organic light-emitting devices (OLEDs) use small molecules or polymers which are built up from conjugated rings and pi-electrons to convert electrical energy into visible light. The innovative feature in this project is the use of metal complexes of molecules which emit from a doublet state (i.e. when the metal has one unpaired electron). This is an idea which has not been tested before in OLEDs and, if successful, it could overcome a major limitation of the current technology. Existing devices use molecules with a singlet or triplet state and this limits their efficiency. In particular, our strategy could lead to more efficient blue emitters. This is essential for full-colour displays and for producing white light in lighting applications. New efficient sources of white light are urgently needed as lighting accounts for more than 20% of the UK's energy consumption. (ii) Enhancing Performance of Organic Solar Cells. It is well known that conjugated organic molecules can capture sunlight and convert it into electricity. However, the power conversion efficiency is very low (only about 6%) i.e. 94% of solar radiation does not lead to electric current. We will explore an innovative way of improving this efficiency. When the molecules in a solar cell absorb sunlight, it is crucial to channel this energy between molecules in a precise way to get an efficient output of electricity. A major problem is how to prevent the charged molecular states from recombining (quenching) - a process which does not lead to electricity. We will explore the use of low-energy triplet states to overcome this problem. The advantage of triplet states is that they have longer lifetimes and can therefore move further within the molecules and are less likely to recombine. A new device architecture will be developed that could harness triplets and generate electricity more efficiently.(iii) Reducing atmospheric carbon dioxide. We are all aware of the huge environmental problems of the increasing levels of carbon dioxide in the atmosphere. We propose a new approach to converting carbon dioxide into fuel feedstocks. The principle is this: conjugated polymers absorb light efficiently and then transfer their electrons to nanoparticles or nanotubes. Instead of producing current (as in a solar cell) these charges will be used to convert carbon dioxide into useful fuel molecules, such as methane or ethanol (which could be used instead of oil or coal). Our scheme for achieving this uses organometallic complexes which can capture carbon dioxide on the surface of the nanoparticles.We are in contact with industrial collaborators who will provide input to facilitate future exploitation of promising results.