title: A benzodithiophene-based novel electron transport layer for a highly efficient polymer solar cell.
abstract: We designed and synthesized a novel conjugated polyelectrolyte (CPE), poly{3-[2-[4,8-bis(2-ethyl-hexyloxy)-6-methyl-1,5-dithia-s-indacen-2-yl]-9-(3-dimethylamino-propyl)-7-methyl-9H-fluoren-9-yl]-propyl}-dimethyl-amine (PBN). We employed PBN as an electron-transporting layer on a ZnO layer and constructed a highly efficient, inverted structure device consisting of a mixture of poly({4,8-bis[(2-ethylhexyl)oxy]benzo[1,2-b:4,5-b']dithiophene-2,6-diyl}{3-fluoro-2-[(2-ethylhexyl)carbonyl]thieno[3,4-b]thiophenediyl}) (PTB7) and PC70BM, achieving a high power conversion of up to 8.6%, constituting a 21.1% improvement over the control device performance (7.1%) prepared without a PBN layer. This result was ascribed to the reduced interfacial resistance and the improved charge transport and collection through the PBN electron transport layer.
authors.affiliation: Department of Chemical Engineering, Pohang University of Science and Technology , 77 Cheongam-Ro, Nam-Gu, Pohang, Gyeongbuk 790-784, Korea.
authors.forename: Hong Il
authors.initials: HI
authors.lastname: Kim
authors.forename: Thi Thu Trang
authors.initials: TT
authors.lastname: Bui
authors.forename: Guan-Woo
authors.initials: GW
authors.lastname: Kim
authors.forename: Gyeongho
authors.initials: G
authors.lastname: Kang
authors.forename: Won Suk
authors.initials: WS
authors.lastname: Shin
authors.forename: Taiho
authors.initials: T
authors.lastname: Park
keywords: PBN; conjugated polyelectrolyte; electron transport layer; polymer solar cell; water-/alcohol-soluble polymers