Engineering electrochemical devices: Photosynthetic solar cells and high power capacitors

电化学活性材料将被研究，目的是提供低成本的太阳能收集——包括内置的能量储存，以及高功率的超级电容器。光合蛋白复合物，也被称为反应中心，吸收光并分离电荷。这个过程以近乎完美的量子效率进行（几乎每个光子都转化为电荷）。目标是制造利用这些蛋白质或它们的合成类似物的太阳能电池，以合理的能量转换效率产生电能。原则上，基于反应中心中可用的电子状态，最高可达27.5%的能量转换效率是可能的（通过基因改造）。以前的工作已经证明了发电使用光电化学结构非常类似于染料敏化太阳能电池。我们的目标是克服导致效率远低于1%的严重挑战，包括缺乏选择性电极和光吸收不良。我们小组提出了独特的实施方案来克服这些挑战。一种新颖的电池设计使良好的光吸收和内置能量存储。性能差的一个关键原因是缺乏选择性的电极，导致不良的电荷转移动力学。这将通过采用半导体电极来克服，在半导体电极中，带定位有利于从一个介质转移电荷，并限制另一个介质转移电荷。通过这些和其他改进，我们希望生产出光电化学电池，其功率转换效率超过10%，并能储存数小时的能量。从长远来看，人们希望这种方法将导致一种商业上相关的、环境友好的从阳光中产生电能的方法。

Electrochemically active materials will be investigated that aim to provide low cost solar energy harvesting - including built-in energy storage, as well as high power supercapacitors. Photosynthetic protein complexes, also known as reaction centres, absorb light and separate electrical charge. The process is performed with near perfect quantum efficiency (almost every photon is converted to charge). The objective is to create solar cells that employ these proteins, or their synthetic analogs, to generate electrical energy with reasonable power conversion efficiency. In principle -based on the electronic states available in reaction centres - ultimate power conversion efficiencies of as high as 27.5 % are possible (with genetic modification). Previous work has demonstrated generation using photoelectrochemical configurations very similar to dye-sensitized solar cells. We aim to overcome serious challenges that have led to efficiencies well below 1 % including the lack of selectively of electrodes and poor light absorption. Our group has proposed unique implementation to overcome these challenges. A novel cell design enables good light absorption and built-in energy storage. A key reason for poor performance are lack of selectivity of electrodes resulting in poor charge transfer kinetics. This will be overcome by employing semiconductor electrodes, in which band positioning favours charge transfer from one mediator and restricts that of the other. With these and other modifications we hope to produce photo-electrochemical cells that demonstrate power conversion efficiencies in excess of 10 %, and store energy over a period of hours. In the longer term it is hoped that the approach will lead to a commercially relevant and environmentally friendly method of producing electrical energy from sunlight.