Macromolecules, Vol.50, No.17, 6945-6953, 2017
Efficient Blue, Green, and Red Electroluminescence from Carbazole-Functionalized Poly(spirobifluorene)s
Based on a carbazole-functionalized polyspirobifluorene with high fluorescence quantum yield and deep-blue emission, a series of blue-, green-, and red-emitting polymers have been successfully developed by independently incorporating dibenzothiophene-S,S-dioxide (3,7SO), 4,7-diphenylbenzothiadiazole (DPBT), and 4,7-dithienylbenzothiadiazole (DTBT) as the copolymerized units to tune the emission color in the whole visible region. The effect of their loadings on the electrochemical, photophysical, and electroluminescent properties is investigated in detail. It is found that PCzSF-3,7SO15, PCzSF-DPBT15, and PCzSF-DTBT03 show the best blue, green, and red device performance, revealing state-of-the-art luminous efficiencies of 5.6, 21.6, and 4.4 cd A(-1) along with CIE coordinates of (0.16, 0.16), (0.32, 0.60), and (0.61, 0.34), respectively. The results clearly indicate that the carbazole-functionalized polyspirobifluorene is a promising platform to construct high-efficiency multicolor polymers suitable for PLEDs.