Jump to main content
Jump to site search

Issue 1, 2010
Previous Article Next Article

Dithienopyrrole-based donor–acceptor copolymers: low band-gap materials for charge transport, photovoltaics and electrochromism

Author affiliations

Abstract

A series of highly soluble donor–acceptor (D–A) copolymers containing N-(3,4,5-tri-n-decyloxyphenyl)-dithieno[3,2-b:2′,3′-d]pyrrole (DTP) or N-(2-decyltetradecyl)-dithieno[3,2-b:2′,3′-d]pyrrole (DTP′) as donor and three different acceptors, 4,7-dithien-2-yl-[2,1,3]-benzothiadiazole, 4,9-dithien-2-yl-6,7-di-n-hexyl-[1,2,5]thiadiazolo[3,4-g]quinoxaline and 4,8-dithien-2-yl-2λ4δ2-benzo[1,2-c;4,5-c′]bis[1,2,5]thiadiazole (BThX, X = BTD, TQHx2, BBT, respectively) were synthesized by Stille coupling polymerizations. The optical and electrochemical properties of these copolymers were investigated, along with their use in field-effect transistors and photovoltaic devices. The band gaps (eV) estimated from UV-vis-NIR spectra and electrochemical measurements of the copolymers varied from ca. 1.5–0.5 eV, and were consistent with quantum-chemical estimates extrapolated using density functional theory. Oxidative and reductive spectroelectrochemistry of the copolymers indicated they can be both p-doped and n-doped, and three to four differently colored redox states of the polymers can be accessed through electrochemical oxidation or reduction. The DTP-BThBTD and DTP-BThTQHx2 copolymers exhibited average field-effect hole mobilities of 1.2 × 10−4 and 2.2 × 10−3 cm2/(Vs), respectively. DTP-BThBBT exhibited ambipolar field-effect characteristics and showed hole and electron mobilities of 1.2 × 10−3 and 5.8 × 10−4 cm2/(Vs), respectively. Bulk heterojunction photovoltaic devices made from blends of the copolymers with 3′-phenyl-3′H-cyclopropa[1,9](C60-Ih)[5,6]fullerene-3′-butanoic acid methyl ester (PCBM) (1:3 weight ratio) exhibited average power conversion efficiencies as high as 1.3% under simulated irradiance of 75 mW/cm2.

Graphical abstract: Dithienopyrrole-based donor–acceptor copolymers: low band-gap materials for charge transport, photovoltaics and electrochromism

Back to tab navigation

Supplementary files

Publication details

The article was received on 04 Aug 2009, accepted on 19 Oct 2009 and first published on 16 Nov 2009


Article type: Paper
DOI: 10.1039/B915940A
Citation: J. Mater. Chem., 2010,20, 123-134
  •   Request permissions

    Dithienopyrrole-based donor–acceptor copolymers: low band-gap materials for charge transport, photovoltaics and electrochromism

    X. Zhang, T. T. Steckler, R. R. Dasari, S. Ohira, W. J. Potscavage, S. P. Tiwari, S. Coppée, S. Ellinger, S. Barlow, J. Brédas, B. Kippelen, J. R. Reynolds and S. R. Marder, J. Mater. Chem., 2010, 20, 123
    DOI: 10.1039/B915940A

Search articles by author

Spotlight

Advertisements