Efficient modification of transparent graphene electrodes by electron beam irradiation for organic solar cells

•Electron beam (EB)-based modification of graphene was investigated.•The chemical and crystalline structure of the graphene was successfully changed by EB irradiation.•The modified graphene was directly applied as a transparent electrode for organic solar cells.•The device with the modified graphene electrode exhibited enhanced device-performance. A simple, solvent-free, and efficient electron beam (EB)-irradiation based modification of graphene and its use as a transparent electrode in organic solar cells (OSCs) were described in this research. A chemical vapor deposition (CVD)-prepared graphene was irradiated by an energetic EB for various irradiation times to modify its chemical and electrical properties. The analytical results revealed that the graphene was successfully modified by EB irradiation-induced oxidation and amorphization, and thereby resulting in the increase in its sheet resistance and work function. Moreover, on the basis of the results of the OSC-performance test, the OSCs with the graphene electrode modified at the irradiation time of 5s exhibited the highest power conversion efficiency of 2.76%, which is much better than that with a non-irradiated graphene electrode. Therefore, it can be confirmed that the EB irradiation could be used in effectively tuning the graphene's properties and the resulting EB-treated graphene can be directly applicable as a transparent electrode and beneficial for high-performance organic electronics.