title: Improved high-efficiency organic solar cells via incorporation of a conjugated polyelectrolyte interlayer.
abstract: The power conversion efficiencies of bulk heterojunction (BHJ) solar cells can be increased from 5 to 6.5% by incorporating an ultrathin conjugated polyelectrolyte (CPE) layer between the active layer and the metal cathode. Poly[N-9''-heptadecanyl-2,7-carbazole-alt-5,5-(4',7'-di-2-thienyl-2',1',3'-benzothiadiazole)] (PCDTBT) and [6,6]-phenyl C(71) butyric acid methyl ester (PC(71)BM) were chosen for the photoactive layer. CPEs with cationic polythiophenes, in both homopolymer and block copolymer configurations, were used to improve the electronic characteristics. The significant improvement in device performance and the simplicity of fabrication by solution processing suggest a promising and practical pathway for improving polymer solar cells with high efficiencies.
authors.affiliation: Center for Polymers and Organic Solids, Department of Physics, University of California, Santa Barbara, California 93106, USA.
authors.forename: Jung Hwa
authors.initials: JH
authors.lastname: Seo
authors.forename: Andrea
authors.initials: A
authors.lastname: Gutacker
authors.forename: Yanming
authors.initials: Y
authors.lastname: Sun
authors.forename: Hongbin
authors.initials: H
authors.lastname: Wu
authors.forename: Fei
authors.initials: F
authors.lastname: Huang
authors.forename: Yong
authors.initials: Y
authors.lastname: Cao
authors.forename: Ullrich
authors.initials: U
authors.lastname: Scherf
authors.forename: Alan J
authors.initials: AJ
authors.lastname: Heeger
authors.forename: Guillermo C
authors.initials: GC
authors.lastname: Bazan