Synthesis, electroluminescence, and photovoltaic cells of new vinylene-copolymers with 4-(Anthracene-10-yl)-2,6-diphenylpyridine segments

Three new soluble vinylene-copolymers F, C, and P that contain 4-(anthracene-10-yl)-2,6-diphenylpyridine as common segment and fluorene, carbazole, or phenylene, respectively, as alternating segment were prepared by Heck coupling. The glass transition temperature was high for F and C (110 and 117°C), whereas was lower than 25°C for P. The polymers were stable up to ∼ 300°C. They emitted blue-green light with maximum located at wavelength of 456-550 nm, which was of the order F < C < P. The photoluminescence quantum efficiency in THF solution was ∼ 30% for F and P and only 5% for C. All three copolymers were used as active layers for polymer light emitting diodes (PLEDs) and organic photovoltaic cells. The double PLEDs with configuration of indium-tin oxide (ITO)/poly(ethylenedioxythiophene (PEDOT) : poly(styrenesulfonate)(PSS)/Copolymer F, C, or P/TPBI(1,3,5-tris(2- N-phenylbenzimidazolyl)benzene)/Ca/Al were fabricated. Copolymer P emitted green light with maximum brightness of 28 cd/m² and a current yield of 0.85 cd/A. Organic photovoltaics with the configuration of ITO/PEDOT : PSS/ Copolymer and [6,6]-phenyl-C61-butyric acid methyl ester blend (1 : 1) /Ca/Al were also fabricated. Copolymer P showed the highest power conversion efficiency of 0.034%.