Carbon Nanosheets as Nanostructured Electrode in Organic Photovoltaic Devices

With increasing energy costs, the need for cheap renewable energy sources becomes significantly more important. Organic solar cells offer the potential for light-weight, flexible devices with potentially low material cost. Despite significant improvements over the last couple of years, the maximum power conversion efficiency of organic photovoltaic devices is still about 5%, mainly due to the low charge carrier mobility in the organic materials. The low mobility leads to increases in both film resistance and charge carrier recombination, therefore reducing the photocurrent and the efficiency of devices. The low mobility can be addressed by reducing the distance between the site of charge creation in the film and the charge collecting electrode. Therefore, this project will explore the use of a nanostructured electrode consisting of free-standing carbon nanosheets. The volume between the sheets will be filled with photoactive material, thereby reducing the distance charges have to travel to the collecting electrode. Commercial Applications and other Benefits as described by the awardee: The technology should significantly improve the power conversion efficiency of organic solar cells, enabling further market acceptance. Applications include rooftop photovoltaic systems and light weight, flexible solar cells integrated into tents, textiles, and small electronic devices (i.e. cell phones, PDAs, etc.).