Exciton Splitting (image) Stanford University Caption Stanford scientists may have resolved a debate over how organic solar cells turn sunlight into electricity. The question: What causes electron-hole pairs (excitons) to split apart? The likely answer: a gradient at the solar cell interface between disordered polymers and ordered buckyballs splits the exciton, allowing the electron (purple) to escape and produce an electric current. Credit Koen Vandewal, Stanford University Usage Restrictions Graphics, photographs and videos provided by the Precourt Institute for Energy at Stanford University are to be used - with appropriate credit - for editorial purposes only. Flopping, altering, editing or otherwise embellishing these images and audio clips in any way that changes the editorial content of these images and audio clips is prohibited. Permission is for one-time use only. Supplied image file must be deleted after use Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.