The research shows that films used in organic cells, which are produced more slowly with additives, generally perform better than the more rapidly formed films. Aerial view of Argonne National Laboratory. Image:John Hill for Argonne National Laboratory/Wikimedia Commons Researchers at the U.S. Argonne-Northwestern Solar Energy Research Center (ANSER), a collaboration between Northwestern University and the U.S. Department of Energy’s (DOE) Argonne National Laboratory, are seeking to improve the molecular microstructures of organic solar cells by using additives. The scientists have developed the photoactive layer of the cell from thin film, which was produced via spin coating. In the process, the material used for creating the thin film was dissolved in a solvent, on a spinning surface. This, the research group said, has enabled it to observe through an X-ray beamline how the film’s crystal structure evolves in real time. The study, published in scientific review Advanced Materials, stresses how certain additives can considerably affect both the time it takes for the film’s structure to stop changing, and the intermediate structures the film adopts during evolution. Furthermore, it shows that films that are produced more slowly with additives, generally perform better than the more rapidly formed films. “Producers of solar cells will often go to the next step in production quickly after spin coating, which has the potential to lock the morphology while the structure is still forming. This can significantly affect the cell’s performance, positively and negatively,” said the research coordinator Eric Manley. More complex structures will now be analyzed, and different choices on how to improve the cells’ performance will also be taken into account, the research team concluded. Emiliano joined pv magazine in March 2017. He has been reporting on solar and renewable energy since 2009. More articles from Emiliano Bellini
Scientists at the US ANSER (Argonne-Northwestern Solar Energy Research Center) have developed the photoactive layer of organic solar cells from thin film, using a solvent on a spinning surface to improve the molecular microstructures. The study, published in the journal Advanced Materials, highlighted how additives can affect the development of the film and that those produced more slowly with additives often perform better than those formed more quickly. The research team at Argonne-Northwestern Solar Energy Research Center said more complex structures will now be analysed, with different choices on how the cells' performance is improved to be taken into account.