Synthesis of a conjugated pyrrolopyridazinedione-benzodithiophene (PPD-BDT) copolymer and its application in organic and hybrid solar cells

Astrid-Caroline Knall; Andrew O F Jones; Birgit Kunert; Roland Resel; David Reishofer; Peter W Zach; Mindaugas Kirkus; Iain McCulloch; Thomas Rath

doi:10.1007/s00706-017-1949-1

Synthesis of a conjugated pyrrolopyridazinedione-benzodithiophene (PPD-BDT) copolymer and its application in organic and hybrid solar cells

Monatsh Chem. 2017;148(5):855-862. doi: 10.1007/s00706-017-1949-1. Epub 2017 Mar 30.

Authors

Astrid-Caroline Knall^{1

2}, Andrew O F Jones³, Birgit Kunert³, Roland Resel³, David Reishofer¹, Peter W Zach⁴, Mindaugas Kirkus^{2

5}, Iain McCulloch^{2

5}, Thomas Rath¹

Affiliations

¹ Institute for Chemistry and Technology of Materials (ICTM), NAWI Graz, Graz University of Technology, Stremayrgasse 9, 8010 Graz, Austria.
² Department of Chemistry and Centre for Plastic Electronics, Imperial College London, Imperial College Road, London, SW7 2AZ UK.
³ Institute of Solid State Physics, Graz University of Technology, Petersgasse 16, 8010 Graz, Austria.
⁴ Institute of Analytical Chemistry and Food Chemistry, Graz University of Technology, Stremayrgasse 9, 8010 Graz, Austria.
⁵ King Abdullah University of Science and Technology (KAUST), SPERC, Thuwal, 23955-6900 Saudi Arabia.

Abstract

Abstract: Herein, we describe the synthesis and characterization of a conjugated donor-acceptor copolymer consisting of a pyrrolopyridazinedione (PPD) acceptor unit, and a benzodithiophene (BDT) donor unit. The polymerization was done via a Stille cross-coupling polycondensation. The resulting PPD-BDT copolymer revealed an optical bandgap of 1.8 eV and good processability from chlorobenzene solutions. In an organic solar cell in combination with PC₇₀BM, the polymer led to a power conversion efficiency of 4.5%. Moreover, the performance of the copolymer was evaluated in polymer/nanocrystal hybrid solar cells using non-toxic CuInS₂ nanocrystals as inorganic phase, which were prepared from precursors directly in the polymer matrix without using additional capping ligands. The PPD-BDT/CuInS₂ hybrid solar cells showed comparably high photovoltages and a power conversion efficiency of 2.2%.

Keywords: Fullerenes; Hybrid nanomaterials; Materials science; Nanostructures; Photovoltaics; Polymerization.