Benzobisthiazole-Based Donor–Acceptor Copolymer Semiconductors for Photovoltaic Cells and Highly Stable Field-Effect Transistors

  • 10.1021/ma201128x
  • Macromolecules
  • p 7207-7219, Volume 44, Issue 18,
  • journal-article
Six new donor–acceptor copolymers based on benzobisthiazole and various donor moieties (dithienosilole, dithienopyrrole, cyclopentadithiophene, carbazole, benzodithiophene, and bithiophene) were synthesized, characterized, and used in field-effect transistors and solar cells. The series of polybenzobisthiazoles with donor–acceptor architecture have optical band gaps of 1.83–2.18 eV, have identical LUMO energy levels (∼−3.3 eV), and have a HOMO energy level that varied from −4.79 eV in PBTDTP to −5.71 eV in PBTHDDT. X-ray diffraction of the polybenzobisthiazole films showed a lamellar crystalline structure with an interlayer d-spacing of 1.56 nm in PBTOT to 1.83 nm in PBTDTP and 2.12 nm in PBTHDDT and a short π-stacking distance (0.353–0.378 nm). The highly crystalline nature of the polybenzobisthiazoles facilitated high field-effect carrier mobility (up to 0.011 cm 2 /(V s)), which remained very stable under ambient conditions for 2 years. Bulk heterojunction solar cells made from one of the benzobisthiazole-based copolymers gave a power conversion efficiency of up to 3.0% under 100 mW/cm 2 AM1.5 sunlight illumination in air.


Good synthesis; product easy to isolate

Synthesized 2,6-Bis(3-dodecylthiophen-2-yl)benzobisthiazole following the procedure.

(1) The reaction was reproduced with higher yields (>25%).

(2) Added the 2-carboxylaldehydethiophene derviative by portions, used longer reaction time (24hs) and removed the acid gas...