title: Regioisomeric Effects of Donor-Acceptor-Acceptor' Small-Molecule Donors on the Open Circuit Voltage of Organic Photovoltaics.
abstract: Donor-acceptor-acceptor' small-molecule donors are synthesized to investigate regioisomeric effects on organic photovoltaic device performance. Cross-conjugation in 2-((7-(N-(2-ethylhexyl)-benzothieno[3,2-b]thieno[3,2-d]pyrrol-2-yl)benzo[c][1,2,5]thiadiazol-4-yl)methylene)malononitrile leads to an increased open-circuit voltage compared with its isomer 2-((7-(N-(2-ethylhexyl)-benzothieno[3,2-b]thieno[2,3-d]pyrrol-2-yl)benzo[c][1,2,5]thiadiazol-4-yl)methylene)malononitrile. A correlation is then established between molecular conjugation length and orbital energies, and hence open-circuit voltage.
authors.affiliation: Applied Physics Program, University of Michigan, Ann Arbor, MI, 48109, USA.
authors.forename: Xiaozhou
authors.initials: X
authors.lastname: Che
authors.affiliation: Department of Chemistry, National Taiwan University, Taipei, 10617, Taiwan.
authors.forename: Chin-Lung
authors.initials: CL
authors.lastname: Chung
authors.affiliation: Department of Electrical Engineering and Computer Science, University of Michigan, Ann Arbor, MI, 48109, USA.
authors.forename: Xiao
authors.initials: X
authors.lastname: Liu
authors.affiliation: Department of Chemistry, National Taiwan University, Taipei, 10617, Taiwan.
authors.forename: Shu-Hua
authors.initials: SH
authors.lastname: Chou
authors.affiliation: Department of Chemistry, National Taiwan University, Taipei, 10617, Taiwan.
authors.forename: Yi-Hung
authors.initials: YH
authors.lastname: Liu
authors.affiliation: Department of Chemistry, National Taiwan University, Taipei, 10617, Taiwan. kenwong@ntu.edu.tw.|Institute of Atomic and Molecular Science, Academia Sinica, Taipei, 10617, Taiwan. kenwong@ntu.edu.tw.
authors.forename: Ken-Tsung
authors.initials: KT
authors.lastname: Wong
authors.affiliation: Applied Physics Program, University of Michigan, Ann Arbor, MI, 48109, USA. stevefor@umich.edu.|Department of Electrical Engineering and Computer Science, University of Michigan, Ann Arbor, MI, 48109, USA. stevefor@umich.edu.|Department of Physics and Department of Materials Science and Engineering, University of Michigan, Ann Arbor, MI, 48109, USA. stevefor@umich.edu.
authors.forename: Stephen R
authors.initials: SR
authors.lastname: Forrest
keywords: conjugation length; dipoles; organic solar cells