Photovoltaic Devices\n

Photovoltaic Devices
Solar power currently supplies less than 1% of the total US demand for energy. If it is to increase its share, the cost of solar power must decrease significantly. Following the example of the soft semiconductors used in laser printers and photocopiers, the advantage of soft semiconductors in this application is the potential for lower cost fabrication. But at present, solid-state photovoltaics built from soft semiconductors are limited to power efficiencies of approximately 5%, much less than the 25% conversion efficiency of high performance Si cells.

Our particular approach employs device architectures and materials from photosynthesis, the biological solar energy conversion system evolved over the last 2 billion years. Photosynthetic structures in biology are examples of an entirely different architecture for electronics. Photosynthesis relies on molecular circuits with Ångstrom-scale precision by soft protein scaffolds. These devices are self assembled within living organisms, and possess power conversion efficiencies that are expected to approach or exceed the best Si devices. In our initial work, we have integrated photosynthetic protein-molecular complexes in solid state devices for the first time.