Title
Highly Efficient and Balanced Charge Transport in Thieno[3,4-c]pyrrole- 4,6-Dione Copolymers: Dramatic Influence of Thieno[3,2-b]thiophene Comonomer on Alignment and Charge Transport
Author
Tina Weller, Kira Rundel, Gert Krauss, Christopher R. McNeill, Mukundan Thelakkat
Year
2018
Journal
The Journal of Physical Chemistry C
Abstract
The design, synthesis, characterization and application of a novel series of copolymers based on the electron deficient thieno[3,4-c]pyrrole-4,6-dione building block, copolymerized with either thieno[3,2-b]thiophene (PTPDTT) or thiophene (PTPDT) is reported. High molecular weights were obtained for PTPDTT via Stille polycondensation. For the PTPDTs, different molecular weights were achieved by varying the polymerization conditions. The increase in molecular weight (PTPDT-2) favors face-on alignment and increases the charge carrier mobility. GIWAXS measurements reveal higher crystallinity for PTPDTT with up to five orders of lamellar stacking compared to PTPDTs. All polymers show ambipolar charge transport with highly balanced hole and electron mobilities in OFETs, which improve considerably upon thermal annealing. A shift of comonomer from simple thiophene in PTPDT-2 to planar and electron-dense thienothiophene in PTPDTT drastically changes the alignment from face-on to edge-on fashion. Consequently, the charge carrier mobility increases considerably by one order of magnitude in PTPDTT, reaching excellent charge carrier mobilities for both holes (0.11 cm2 V-1 s-1) and electrons (0.17 cm2 V-1 s-1). PTPDTT was tested as a donor material in combination with PC71BM as well as an acceptor material along with a donor polymer.
Instrument
FP-8600
Keywords
Photoluminescence, Polymers, Solid state, Materials