title: Ultrathin organic solar cells with graphene doped by ferroelectric polarization.
abstract: Graphene has been employed as transparent electrodes in organic solar cells (OSCs) because of its good physical and optical properties. However, the electrical conductivity of graphene films synthesized by chemical vapor deposition (CVD) is still inferior to that of conventional indium tin oxide (ITO) electrodes of comparable transparency, resulting in a lower performance of OSCs. Here, we report an effective method to improve the performance and long-term stability of graphene-based OSCs using electrostatically doped graphene films via a ferroelectric polymer. The sheet resistance of electrostatically doped few layer graphene films was reduced to ∼70 Ω/sq at 87% optical transmittance. Such graphene-based OSCs exhibit an efficiency of 2.07% with a superior stability when compared to chemically doped graphene-based OSCs. Furthermore, OSCs constructed on ultrathin ferroelectric film as a substrate of only a few micrometers show extremely good mechanical flexibility and durability and can be rolled up into a cylinder with 7 mm diameter.
authors: School of Electrical and Electronic Engineering, Yonsei University , Seoul 120-749, Korea.
authors: Keumok
authors: K
authors: Kim
authors: Sang-Hoon
authors: SH
authors: Bae
authors: Chee Tat
authors: CT
authors: Toh
authors: Hobeom
authors: H
authors: Kim
authors: Jeong Ho
authors: JH
authors: Cho
authors: Dongmok
authors: D
authors: Whang
authors: Tae-Woo
authors: TW
authors: Lee
authors: Barbaros
authors: B
authors: Özyilmaz
authors: Jong-Hyun
authors: JH
authors: Ahn