Synthesis, optical and electroluminescent properties of novel polyfluorene/carbazole-based conjugated polyelectrolytes and their precursors

作     者：Wei CAO Haixing DONG Fei HUANG Huilin SHEN Yong CAO 

作者机构：Institute of Polymer Optoelectronic Materials and Devices Key Laboratory of Specially Functional Materials of the Ministry of Education South China University of Technology 

出 版 物：《Frontiers of Optoelectronics》 (光电子前沿(英文))

年 卷 期：2008年第1卷第Z2期

页      面：299-304页

学科分类：08[工学] 0805[工学-材料科学与工程（可授工学、理学学位）] 080502[工学-材料学] 

基　　金：supported by the National Natural Science Foundation of China (Grant No. 50433030) research grants from Ministry of Science and Technology (Grant No. 2002CB613402) 

主　　题：conjugated polyelectrolytes electroluminescence carbazole polyfluorene 

摘      要：A series of novel aminoalkyl-substituted fluorene/carbazole-based main chain copolymers with benzothiadiazole(BTDZ) of different contents: poly[3,6-(N-(2-ethylhexyl)carbazole)-(9,9-bis(3 -(N,N-dimethylamino)propyl)-2,7-fluorene)-4,7-(2,1,3-benzothiadiazole)](PCzN-BTDZ) were synthesized by Suzuki coupling reaction. Through a postpolymerization treatment on the precursor polymer, a corresponding quaternized ammonium polyelectrolyte derivatives: poly[3,6-(N-(2-ethylhexyl)carbazole)-(9,9-bis(3 -((N,N-dimethyl)-N-ethylammonium) propyl)-2, 7-fluorene)-4, 7-( 2, 1,3-benzothiadiazole)] dibromide(PCzNBr-BTDZ) were obtained. It was found that devices from such polymers with high work-function metal cathode such as Al showed similar device performance to that by using low work-function cathode such as Ba, indicating the excellent electron injection ability of these *** efficient energy transfer from fluorene-carbazole segment to the narrow band gap BTDZ site for both the neutral and the quaternized copolymers was also observed. The addition of BTDZ into the polymer main chain can also improve polymer LED(PLED)device performance. When poly(3,4-ethylenedioxythiophene)(PEDOT)/poly(vinylcarbazole)(PVK) was used as an anode buffer, the external quantum efficiency of the copolymer PCzN-BTDZ1 was 0.99%, which was much higher than the copolymer PCzN without the incorporation of BTDZ in the same device configuration.