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.

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.