An international team of scientists working with polymer-fullerene solar cells has developed a process of fluorination, which demonstrated a significant boost in cell efficiency. According to Moscow Institute of Physics and Technology, the discovery could assist the development of new thin film solar materials. structure of a repeating unit in the polymer chain without fluorine (left) and after fluorination (right) Image: Elena Khavina/MIPT A group of scientists from France, Russia and Kazakhstan has developed a fluorination technique which provided a significant efficiency boost to solar cells based on organic polymer material. The team worked with polymer:fullerene solar cells, and found that the process of incorporating fluorine atoms into the polymer increased cell efficiency from 3.7% to 10.2%. The researchers note that while this efficiency is still well below current commercial standards, the size of the improvement gained here demonstrates their potential: “Perhaps with further tweaks organic solar cells could outperform their polysilicon based counterparts,” says the release from Moscow Institute of Physics and Technology, which participated in the study alongside University of Strasbourg, University of Lyon, Institut de Sciences des Matériaux de Mulhouse, Synchrotron SOLEIL in France, and Kazakhstan’s Nazarbayev University. Their study, ‘Face-on orientation of fluorinated polymers conveyed by long alkyl chains: a prerequisite for high photovoltaic performances,’ Published in the Royal Society of Chemistry’s Journal of Materials Chemistry A, concludes that fluorination and ‘functionalization by bulky alkyl side chains’ are both necessary to achieve efficiencies above 10%, at least with the polymer being studied here. The polymer was produced in a number of different configurations, and then its structure was again changed by adding fluorine atoms. According to co-author Dimitri Ivanov, the challenge was to “optimize solar cell efficiency by picking the right molecular energy levels of the donor and the acceptor, while also creating the appropriate supramolecular structure that would facilitate charge transport to the electrodes.” Mark Hutchins joined pv magazine in September 2016 as production editor of the monthly global title. Mark also works online reporting on upstream technology and markets, as well as newly emerging solar regions. More articles from Mark Hutchins
Scientists from France, Russia and Kazakhstan have developed a method of fluorination which radically increased the efficiency of an organic solar cell. The team found incorporating fluorine atoms into a polymer-fullerene solar cell resulted in efficiency levels rising from 3.7% to 10.2%, according to a study published in the Royal Society of Chemistry’s Journal of Materials Chemistry A. “Fluorine is one of the most abundant elements on Earth but it has been difficult for researchers to use this element as a source of energy because its abundance makes it hard to extract using conventional