EXPLORER; Excitonic Polymer Organic Devices for Energy

我们提出了三个冒险的，跨学科的能源研究领域内的项目。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、化学和物理传感器等设备已经在市场上销售--可能就在你的家里和口袋里--而太阳能电池等其他设备正在快速发展。其动机是使用这些新技术可以降低成本、易于制造、具有大面积能力并提高效率。然而，仍然需要更多的研究。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。该团队将研究其属性系统地改变的材料，目的是提高其在三个领域的性能。分子内和分子间的能量转移是一个中心主题。(i)更高效的显示技术和新型照明。有机发光器件（OLED）使用由共轭环和π电子构成的小分子或聚合物将电能转化为可见光。该项目的创新特征是使用从双重态（即当金属具有一个未配对电子时）发射的分子的金属络合物。这是一个以前没有在OLED中测试过的想法，如果成功，它可以克服当前技术的主要限制。现有的器件使用具有单重态或三重态的分子，这限制了它们的效率。特别是，我们的策略可能会导致更有效的蓝光发射器。这对于全色显示器和在照明应用中产生白色光至关重要。由于照明占英国能源消耗的20%以上，因此迫切需要新的高效白色光源。(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获阳光并将其转化为电能。然而，功率转换效率非常低（仅约6%），即94%的太阳辐射不会产生电流。我们将探索一种创新的方式来提高这一效率。当太阳能电池中的分子吸收阳光时，以精确的方式在分子之间传递这种能量以获得有效的电力输出至关重要。一个主要的问题是如何防止带电的分子状态重新组合（猝灭）-一个不会导致电的过程。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具有更长的寿命，因此可以在分子内移动得更远，并且不太可能重组。将开发一种新的设备架构，可以利用三胞胎和更有效地发电。(iii)减少大气中的二氧化碳。我们都意识到大气中二氧化碳含量不断增加所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。其原理是：共轭聚合物有效地吸收光，然后将其电子转移到纳米颗粒或纳米管上。而不是产生电流（如在太阳能电池中），这些电荷将用于将二氧化碳转化为有用的燃料分子，如甲烷或乙醇（可以用来代替石油或煤炭）。为了实现这一目标，我们使用了可以在纳米颗粒表面捕获二氧化碳的有机金属配合物。我们正在与工业合作者接触，他们将提供投入，以促进未来有希望的结果的开发。

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.