N-苯基咔唑取代的蓝光聚(2,7-咔唑)的合成与表征

SYNTHESIS AND CHARACTERIZATION OF BLUE-EMITTING POLY(2,7-CARBAZOLE)S SUBSTITUTED WITH N-PHENYLCARBAZOLE

采用Suzuki聚合方法并通过改变催化剂的投料量,合成了一系列具有不同分子量的N-苯基咔唑取代的蓝光聚(2,7-咔唑),并详细研究了分子量对聚合物的光物理、电化学和电致发光器件性质的影响.结果表明,刚性N-苯基咔唑侧链的引入,能够有效地调控主链之间的相互作用,提高蓝光的色纯度,并使得该系列聚合物的固态荧光量子效率高达0.40.同时,在热退火及器件工作过程中,没有观察到类似聚芴中绿光峰的出现,表明具有良好的光谱稳定性.单层聚合物电致发光器件的最大发光效率为0.33 cd/A,色坐标为(0.18,0.12).

A series of blue-emitting poly（2,7-carbazole）s substituted with N-phenylcarbazole （BCzPCz01- BCzPCzI0） have been synthesized via Suzuki polymerization. By reducing the loading of Pd catalyst from I0%~ to l%e,their number-average molecular weights are correspondingly increased from 27000 to 69000 while their polydispersity indexes （PDI） remain in the range of 2.5 to 3.0. And the effect of the molecular weight on their photophysieal, electrochemical and device properties is then thoroughly investigated for these obtained polymers. Most importantly, the introduction of rigid N-phenylcarbazole can effectively tune the interchain interactions, and improve the color purity of blue emission. As a result, all the polymers show film photoluminescent quantum yields as high as 0.40 and excellent spectral stability,for no green emission often appeared in polyfluorenes is observed here under annealing or electric field conditions. Single layer polymer light-emitting diodes are fabricated with a configuration of indium tin oxide （ITO）/poly（3,4- ethylenedioxythiophene） ： poly （ styrene sulfonic acid ） （ PEDOT： PSS ）/polymer/Ca/A1. Among these polymers, BCzPCz01 exhibits a peak luminous efficiency of 0.33 cd/A with Commission Internationale de L＇ Eelairage （CIE） coordinates of （0. 18,0. 12）. The device performance is improved by about 65% in comparison to that of poly （2,7-earbazole） s substituted with triphenylamine. These interesting results will provide a novel platform for the design of highly efficient stable blue-emitting polymers in the future.