Slow charge generation plays big role in model material for solar cells
(PHYSorg.com Chemistry)

Next-generation devices based on molecular materials have the potential to efficiently use sunlight to produce electricity or to drive chemical reactions. In contrast to commercial solar cells, where absorption of light directly generates charge that can be extracted as electricity, absorption of light by molecular materials creates uncharged energetic states called excitons. The trick to making an effective device is to efficiently convert the excitons into charge. This study uncovered a new mechanism to create charge from excitons. By following excitons in a model molecular material, a team found that lower energy excitons made deep in the bulk play a larger part in generating charge than previously thought.