A series of three small-molecule acceptor–donor–acceptor (A- D-A) compounds with a tetraaryl-1,4-dihydropyrrolo[3,2-b]pyr- role as the central building block were synthesized and fully characterized. These molecules present high thermal stability and suitable HOMO–LUMO energy levels making them feasible electron-donor materials in bulk heterojunction organic solar cells (BHJ-OSC). Moreover, theoretical work predicts of a lack of planarity and no p–p stacking, furthermore. The electron den- sity of the HOMO is distributed on the pyrrole–pyrrole moiety and that of the LUMO is delocalized, in contrast, on the phenyl groups. The organic solar cells deliver an open-circuit voltage of 0.99 V. However, the overall efficiency is limited due to the low charge mobility measured for holes, 10 9 cm2 V 1 s 1.
Pyrrolo[3,2-b]pyrrole as the Central Core of the Electron Donor for Solution-Processed Organic Solar Cells
ChemPlusChem 2017, 82, 1096-1104, DOI: 10.1002/cplu.201700158.