Variable temperature double-optical-modulation apparatus

收集太阳能是本世纪的一项关键努力，因为我们面临着世界化石燃料储量不断减少和温室气体生产造成的环境危机不断增加的问题。太阳能电池技术目前基于硅。用于人类能源消耗的设备产生的太阳能转换效率约为10%，足以满足工业化世界的大部分能源需求，但制造此类设备的成本太高，并产生温室气体。为了收回这些能源成本，需要长达四年的连续运行。这是器件寿命的很大一部分;考虑到硅太阳能电池的加工成本，这对该技术的广泛实施构成了严重障碍。为了让太阳能对我们的能源需求产生更大的影响，我们需要找到替代技术，以减少能源回收期和设备处理成本。该研究计划的重点是共轭聚合物，它现在提供了一个技术上可行的一类溶液加工，成膜半导体。有机光伏二极管（OPVD）目前收到相当大的兴趣，作为候选设备，这项技术。在过去十年中开发的最好的材料显示出了希望，但许多研究小组常规测量的太阳能照明下的OPVD功率转换效率目前仅限于5%。对电子动力学的详细了解对于超越这一效率极限至关重要。我们的目标是测量有机太阳能电池电子应用中重要的过程。我们将这样做，诱导光吸收与光调制，可调光源，并测量非常小的变化，光调制的探测光源通过样品的光透射率，诱导的泵浦光，作为温度和调制频率的函数。了解这些新的和令人兴奋的材料中的电子过程对于有机电子学的进一步发展至关重要，超越了材料和器件参数的增量优化。

Harvesting solar energy is a key endeavour for this century as we face ever-decreasing fossil fuel world reserves and ever-increasing environmental crises emanating from greenhouse gas production. Solar cell technology is currently based on silicon. Devices used for human energy consumption yield solar power conversion efficiencies of around 10%, which is sufficient to meet a significant fraction of energy demands in the industrialised world, but manufacturing such devices costs too much energy and produces greenhouse gases. In order to recover such energetic costs, up to four years of continuous operation are required. This is a significant fraction of the device lifetime; given the processing costs of silicon solar cells, it represents a serious obstacle to widespread implementation of this technology. In order for solar energy to have a more substantial impact on our energy requirements, we need to find alternative technologies that reduce energy payback periods and device processing costs. This research programme focuses on conjugated polymers, which now provide a technologically viable class of solution-processable, film-forming semiconductors. Organic photovoltaic diodes (OPVDs) currently receive considerable interest as candidate devices for this technology. The best materials that have been developed over the last decade show promise but OPVD power conversion efficiencies under solar illumination, measured routinely by numerous research groups, are currently limited to 5%. Detailed understanding of electronic dynamics is critical to surpass this efficiency limit. Our objectives are to measure processes that are important in electronic applications of organic solar cells. We will do so by inducing optical absorption with a photomodulated, tunable light source, and measuring very small changes in the optical transmittance of a photomodulated probe light source through the sample, induced by the pump light, as a function of temperature and modulation frequency. Understanding electronic processes in these new and exciting materials is essential for further development of organic electronics beyond incremental optimisation of materials and device parameters.