Organic photovoltaics have achieved remarkably high efficiencies, but finding optimum combinations of materials for high-performance organic solar cells, which are also economically competitive, still presents a challenge. Researchers from the United States and China have now developed an innovative interlayer material to improve device stability and electrode performance. In the journal Angewandte Chemie, the authors describe their fullerene-spiked, readily processable ionene polymer, which boosts the power conversion efficiency of organic solar cells.