title: Synthesis, characterization and photovoltaic properties of poly(thiophenevinylene-alt-benzobisoxazole)s.
abstract: Herein we report the synthesis of two solution processible, conjugated polymers containing the benzobisoxazole moiety. The polymers were characterized using (1)H NMR, UV-Vis and fluorescence spectroscopy. Thermal gravimetric analysis shows that the polymers do not exhibit significant weight loss until approximately 300 °C under nitrogen. Cyclic voltammetry shows that the polymers have reversible reduction waves with estimated LUMO levels at -3.02 and -3.10 eV relative to vacuum and optical bandgaps of 2.04-2.17 eV. Devices based on blends of the copolymers and [6,6]-phenyl C61 butyric acid methyl ester (PCBM) exhibited modest power conversion efficiencies. Theoretical models reveal that there is poor electron delocalization along the polymer backbone, leading to poor performance. However, the energy levels of these polymers indicate that the incorporation of benzobisoxazoles into the polymer backbone is a promising strategy for the synthesis of new materials.
authors.affiliation: Department of Chemistry, Iowa State University, Ames, IA 50011, USA.
authors.forename: Jared F
authors.initials: JF
authors.lastname: Mike
authors.forename: Kanwar
authors.initials: K
authors.lastname: Nalwa
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Makowski
authors.forename: Daniel
authors.initials: D
authors.lastname: Putnam
authors.forename: Aimée L
authors.initials: AL
authors.lastname: Tomlinson
authors.forename: Sumit
authors.initials: S
authors.lastname: Chaudhary
authors.forename: Malika
authors.initials: M
authors.lastname: Jeffries-El