Self-organization polymer consisting of quinacridone and quaterthiophene units: Coplanar structure between benzene and thiophene linkage

Poly[quinacridone-co-quaterthiophene] (PQCQT) was synthesized through a Suzuki coupling reaction by introducing the characterization and self-assembly of quinacridone and quaterthiophene derivatives. The PQCQT was dissolved in a common organic solvent with an Mn value of 52.9 kg/mol. The optical band gap energy of the PQCQT was similar to the P3HT at 2.12 eV. The energy of the HOMO of the PQCQT was −5.10 eV, and the energy of the LUMO was −2.98 eV. The results of the X-ray diffraction measurement showed that the Lamellar d-spacing (d1) of the out-of-plane PQCQT was 23.2 Å, and the π–π stacking distance (dπ) between the layers was 3.5 Å. A bulk-heterojunction type of polymer solar cell was produced with a structure of ITO/PEDOT:PSS/active-layer/PFN/Al. When the ratio of the PQCQT and PC71BM was 1:2, the device performed best with a power conversion efficiency (PCE) of 2.3%.