Effect of fluorine plasma treatment with chemically reduced graphene oxide thin films as hole transport layer in organic solar cells

•The performance of organic solar cells is improved by fluorine plasma treatments on reduced graphene oxide films.•The work function of graphene oxide film after plasma treatments increases because they consist of covalent bonds with fluorine on the surface of film.•The device fabricated with fluorine doped graphene oxide by SF6 plasma showed the highest FF and PCE of OPVs.