Electron Mobility of Diketopyrrolopyrrole Copolymers Is Robust against Homocoupling Defects

• DOI: 10.1021/acs.chemmater.0c03998
• Publication Date: 2021-01-15T03:54:34Z
• Authors: Qian Wang; Shayan Vazirieh L...; Oleksandr Dolynchuk; Alberto D. Scacca...; Hartmut Komber; Yuejie Guo; Florian Günther; Sibylle Gemming; Robert Magerle; Mario Caironi; Michael Sommer
• Keywords: HOMO/LUMO; Electron Mobility

Structural defects in semiconducting conjugated polymers are usually suspected to deteriorate their properties and device performance therefore complicate batch-to-batch reproducibility. This study investigates homocoupling (hc) copolymers made from dithiazolyldiketopyrrolopyrrole (TzDPPTz) tetrafluorobenzene (F4) by direct arylation polycondensation (DAP). Hc quantified 1H NMR spectroscopy with good accuracy, the effect of several reaction parameters on TzDPPTz hc content resulting PTzDPPTzF4 is investigated detail. A range contents between 0.6 12.4% used for a detailed structure–function relationship study. Experimentally, it observed that cause bathochromically shifted absorption spectra, decrease photoluminescence, lower lowest unoccupied molecular orbital (LUMO) energy level. Thin film morphology, nanostructure, electron mobility probed field-effect devices marginally or not affected. The latter result explained theoretical calculations suggest localization highest occupied defect, but LUMO, being relevant transport. Thus, under these conditions, limiting performance, which makes robust electron-transporting copolymer. These results promising context reproducibility further guide efforts toward more understanding hc–function relationships.