Abstract: A composition including a graft copolymer, having: a linear trunk including at least one non-aromatic vinyl polymer or an unsaturated polyolefin; and at least two grafts attached to said trunk via a chemical bond, each graft having a conjugated polymer, characterized in that said composition further includes: fullerenes and a conjugated polymer; or carbon and/or graphene nanotubes. Also, a photovoltaic module incorporating such a composition, and to the use of said composition for the same purposes. Finally, methods for synthesizing the molecules forming all or part of the composition.