• organic solar cells;
  • conjugated molecules;
  • structure-property relationships;
  • single crystal structure;
  • film morphology;
  • charge mobility
Thumbnail image of graphical abstract

Heteroatom substitutions in the end-groups of three diketopyrrolopyrrole-containing small molecules are investigated to evaluate how such substitutions affect physical properties, charge transport, and the performance in bulk heterojunction solar cells. As reported by Thuc-Quyen Nguyen and co-workers on page 47, the single-crystal structures of three compounds reveal the differences in material properties arise from changes in intra- and intermolecular interactions in the solid state, which are caused by heteroatom substitutions. This study demonstrates a systematic investigation of structure-property relationships in conjugated small molecules.