Molecular Crystals and Liquid Crystals, Vol.685, No.1, 22-28, 2019
Enhanced photovoltaic performance of quinoxaline-based small molecules through incorporating trifluoromethyl substituents
Two D-A-D type quinoxaline-based small molecules have been synthesized by Suzuki coupling reaction for solution-processable organic photovoltaic cells (OPVs). The electron-donating triphenylamine was connected to both ends of an electron-withdrawing 2,3-diphenylquinoxaline core through thiophene bridge to produce QxTPA. In addition, QxCF(3)TPA was formed by introducing strong electron-withdrawing trifluoromethyl (CF3) groups into the para-position of the phenyl ring at the 2,3-position of quinoxaline core in QxTPA to explore their effect on the various properties of small molecules. The finding revealed the significant contributions of CF3 substituents in enhancing the photovoltaic performances of OPVs with QxCF(3)TPA compared to the reference case with QxTPA.
Keywords:Small molecules;organic photovoltaic cell;triphenylamine;2;3-diphenylquinoxaline;trifluoromethyl