Single-step, catalyst-free, and green synthesis of graphene transparent electrode for organic photovoltaics

Graphene is a promising transparent conducting electrode (TCE) for organic photovoltaics (OPVs) due to its outstanding optical and electrical properties. However, the high cost and complexity of graphene synthesis on transparent substrates as well as the use of hazardous carbon sources limits the large-scale application of graphene TCEs. This work reports a single-step synthesis of graphene TCEs on glass substrates for OPVs from plant extract by Radio frequency plasma enhanced chemical vapor deposition. This approach provides fast, cheap, and catalyst-free production of graphene from a sustainable and environmentally-friendly carbon resource.The as-prepared graphene films reveal high quality structure with promising optical and electrical properties. Inverted OPV devices built on the as-synthesized graphene TCEs exhibit 80% of the power conversion efficiency of their indium tin oxide counterparts, and higher short circuit current density and open circuit voltage