Femtosecond Optical Probes of Mesoscopic Materials for Photovoltaics

越来越多的证据表明，我们日益增长的化石燃料消费正在导致气候变化。这些预测给清洁、可再生能源的开发带来了新的紧迫性，这将使世界经济继续保持目前的增长水平，而不会对我们的生态系统造成损害。基于有机或有机/无机杂化材料的光伏电池在过去的十年中表现出了快速的进步，与现有的无机半导体技术相比，在能源、可扩展性和制造成本方面具有优势。最有希望用于有机或混合光伏的材料是基于两个组分的混合物，在两个组分的界面上，光产生的激发分解为形成光电流的电荷。在这些体系中，介观尺度上的混合形态起着至关重要的作用，高效的光伏运行需要较大的界面面积和到电极的载流子渗流路径的存在。这项拟议的工作将建立如何实现这两个目标，使用一种强大的非接触式飞秒时间分辨技术的新组合来研究一系列新型的介观混合物。这种方法将允许同时检测激子扩散和解离、载流子产生、复合和导电性，为光伏材料的优化提供直接线索。与制造光伏设备的研究人员合作，将确保从这些非接触式材料探测器中获得的知识将直接用于提高设备性能。这种结合的方法将使英国在有机电子领域的极高专业知识有效地为其目前减少有害温室气体排放的目标做出贡献。

There is growing evidence that our increasing consumption of fossil fuels is leading to a change in climate. Such predictions have brought new urgency to the development of clean, renewable sources of energy that will permit the current level of world economic growth to continue without damage to our ecosystem. Photovoltaic cells based on organic or organic/inorganic hybrid materials have shown rapid improvements over the past decade, comparing favourably with existing inorganic semiconductor technology on energy, scalability and cost associated with manufacture. The most promising materials for organic or hybrid photovoltaics are based on blends of two components at whose interface light-generated excitations dissociate into charges contributing to a photocurrent. Blend morphology on the meso-scale plays a crucial role in these systems, with efficient photovoltaic operation requiring both large interfacial area and existence of carrier percolation paths to the electrodes. The proposed work will establish how both aims can be achieved, using a powerful new combination of non-contact femtosecond time-resolved techniques to examine a range of novel mesoscopic blends. This methodology will allow the simultaneous examination of exciton diffusion and dissociation, charge-carrier generation, recombination and conductivity, providing direct clues to the optimisation of materials for photovoltaics. Collaborations with researchers working on making photovoltaic devices will ensure that knowledge gained from these non-contact material probes will directly feed into enhancing device performance. This combined approach will allow the UK's exceptionally high expertise in the area of organic electronics to contribute effectively to its current goal of reducing harmful greenhouse gas emission.