title: Flexible, highly efficient all-polymer solar cells.
abstract: All-polymer solar cells have shown great potential as flexible and portable power generators. These devices should offer good mechanical endurance with high power-conversion efficiency for viability in commercial applications. In this work, we develop highly efficient and mechanically robust all-polymer solar cells that are based on the PBDTTTPD polymer donor and the P(NDI2HD-T) polymer acceptor. These systems exhibit high power-conversion efficiency of 6.64%. Also, the proposed all-polymer solar cells have even better performance than the control polymer-fullerene devices with phenyl-C61-butyric acid methyl ester (PCBM) as the electron acceptor (6.12%). More importantly, our all-polymer solar cells exhibit dramatically enhanced strength and flexibility compared with polymer/PCBM devices, with 60- and 470-fold improvements in elongation at break and toughness, respectively. The superior mechanical properties of all-polymer solar cells afford greater tolerance to severe deformations than conventional polymer-fullerene solar cells, making them much better candidates for applications in flexible and portable devices.
authors.affiliation: Department of Chemical and Biomolecular Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 305-701, Republic of Korea.|KI for the NanoCentury, KAIST, Daejeon 305-701, Republic of Korea.
authors.forename: Taesu
authors.initials: T
authors.lastname: Kim
authors.affiliation: KI for the NanoCentury, KAIST, Daejeon 305-701, Republic of Korea.|Department of Mechanical Engineering, KAIST, Daejeon 305-701, Republic of Korea.
authors.forename: Jae-Han
authors.initials: JH
authors.lastname: Kim
authors.affiliation: Department of Chemical and Biomolecular Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 305-701, Republic of Korea.|KI for the NanoCentury, KAIST, Daejeon 305-701, Republic of Korea.
authors.forename: Tae Eui
authors.initials: TE
authors.lastname: Kang
authors.affiliation: Department of Chemical and Biomolecular Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 305-701, Republic of Korea.|KI for the NanoCentury, KAIST, Daejeon 305-701, Republic of Korea.
authors.forename: Changyeon
authors.initials: C
authors.lastname: Lee
authors.affiliation: Department of Chemical and Biomolecular Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 305-701, Republic of Korea.|KI for the NanoCentury, KAIST, Daejeon 305-701, Republic of Korea.
authors.forename: Hyunbum
authors.initials: H
authors.lastname: Kang
authors.affiliation: Department of Materials Science and Engineering, POSTECH, Pohang 790-784, Republic of Korea.
authors.forename: Minkwan
authors.initials: M
authors.lastname: Shin
authors.affiliation: Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA.
authors.forename: Cheng
authors.identifier: http://orcid.org/0000-0001-7192-5471
authors.initials: C
authors.lastname: Wang
authors.affiliation: Department of Chemical and Biomedical Engineering, Florida State University, Tallahassee, Florida 32310, USA.
authors.forename: Biwu
authors.initials: B
authors.lastname: Ma
authors.affiliation: Department of Materials Science and Engineering, POSTECH, Pohang 790-784, Republic of Korea.
authors.forename: Unyong
authors.initials: U
authors.lastname: Jeong
authors.affiliation: KI for the NanoCentury, KAIST, Daejeon 305-701, Republic of Korea.|Department of Mechanical Engineering, KAIST, Daejeon 305-701, Republic of Korea.
authors.forename: Taek-Soo
authors.initials: TS
authors.lastname: Kim
authors.affiliation: Department of Chemical and Biomolecular Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 305-701, Republic of Korea.|KI for the NanoCentury, KAIST, Daejeon 305-701, Republic of Korea.
authors.forename: Bumjoon J
authors.initials: BJ
authors.lastname: Kim