title: Flexible graphene electrode-based organic photovoltaics with record-high efficiency.
abstract: Advancements in the field of flexible high-efficiency solar cells and other optoelectronic devices will strongly depend on the development of electrode materials with good conductivity and flexibility. To address chemical and mechanical instability of currently used indium tin oxide (ITO), graphene has been suggested as a promising flexible transparent electrode but challenges remain in achieving high efficiency of graphene-based polymer solar cells (PSCs) compared to their ITO-based counterparts. Here we demonstrate graphene anode- and cathode-based flexible PSCs with record-high power conversion efficiencies of 6.1 and 7.1%, respectively. The high efficiencies were achieved via thermal treatment of MoO3 electron blocking layer and direct deposition of ZnO electron transporting layer on graphene. We also demonstrate graphene-based flexible PSCs on polyethylene naphthalate substrates and show the device stability under different bending conditions. Our work paves a way to fully graphene electrode-based flexible solar cells using a simple and reproducible process.
authors.affiliation: Department of Electrical Engineering and Computer Science and ‡Department of Materials Science and Engineering, Massachusetts Institute of Technology , Cambridge, Massachusetts 02139, United States.
authors.forename: Hyesung
authors.initials: H
authors.lastname: Park
authors.forename: Sehoon
authors.initials: S
authors.lastname: Chang
authors.forename: Xiang
authors.initials: X
authors.lastname: Zhou
authors.forename: Jing
authors.initials: J
authors.lastname: Kong
authors.forename: Tomás
authors.initials: T
authors.lastname: Palacios
authors.forename: Silvija
authors.initials: S
authors.lastname: Gradečak
keywords: Flexible solar cell; graphene anode; graphene cathode; polymer solar cell