Poly-(p-phenylene vinylenes) with Pendent 2,4-Difluorophenyl and Fluorenyl Moieties: Synthesis, Characterization, and Device Performance

To improve efficiency, processability, and stability, three novel poly-(P-phenylene vinylenes) (PPVs) derivatives (P-a, P-b, and P-c) with pendent 2,4-difluorophenyl and fluorenyl moieties were synthesized via Gilch reaction. Their structures were characterized by H-1 NMR, C-13 NMR, and ELEM. ANAL Compared with those of PPV and MEH-PPV, the absolute quantum efficiencies of these polymers showed remarkable improvement (measured at 38.7, 37.2, and 20.3%, respectively), which can be attributed to the presence of twisted multiaryl segments and fluorine atoms. TGA revealed that the inflection temperatures of their thermal decomposition curves were above 400 degrees C. Double-layered electroluminescent devices with these polymers as light-emitting layers [ITO/PEDOT:PSS/Polymer/Ba/Al] showed peak emissions at 493/515, 503, and 600 run and maximum luminance of 2700, 450, and 4700 cd/m(2) for P-a, P-b, and P-c respectively, with onset voltages of similar to 4 V. (C) 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 2500-2508, 2009