Fabrication of organic photovoltaic devices employing nitrogen-doped graphene nanoribbons is reported herein. Graphene nanoribbons are of interest to organic photovoltaic devices due to their high mobility, high thermal and atmospheric stability, and tensile strength. In this study, we observed that inclusion of graphene nanoribbons as electron acceptors in a P3HT polymer cell decreases the series resistance by providing conductive pathways. Additionally, optical studies confirm an increase in the order of the film by addition of graphene nanoribbons (GNR). The devices containing GNRs have superior performance to those of pristine P3HT. A Voc of 0.51 V, Jsc of -4.07 x 10-5 A/cm2, power conversion efficiency (PCE) of 0.00643, and fill factor of 0.31 was obtained by fabricating a device from P3HT/GNR solutions aged overnight with cyclohexanone. Polymers cells using PCDTBT as a donor and PC71BM as the acceptor were also studied due to the polymer’s significantly different morphology to P3HT. The addition of 2% of graphene nanoribbons provides a conductive pathways for electrons to reach the cathode, an effect observed in the decrease in series resistance, improvement of Jsc of 15%, and an increase in PCE of 18%. The figures of merit for this cell were Voc = 0.92 V, Jsc = -7.34 x 10-3 A/cm2, PCE of 3.41%, and a fill factor of 0.5. To our knowledge this is the first study employing atomically defined graphene nanoribbons in organic photovoltaics, showing promise of the material as current and efficiency enhancers.




Download Full History