| 초록 |
Graphene oxide(GO) is used for anode interlayer of organic photovoltaics(OPVs). Some studies reported high performance and stability of GO compared to PEDOT:PSS. However, solution processed GO has complicated surface composition and low homogeneity, so it is difficult to reproduce and analyze. Here, we treated oxygen plasma on the CVD-grown graphene, which has better reproducibility and homogeneity, and gained GO. We varied plasma treatment time with same plasma power and pressure, and it is changed that oxidation level and ratio of C-O and C=O functional groups. Different surface composition affected to surface potential and band gap of the material, and these are directly related to carrier extraction and selection on the OPV devices. The oxidized graphene with the highest C=O ratio and sufficient oxidation level has the proper HOMO level for usual donor materials. The device performance using the graphene showed comparable performance and better stability. |
