A series of solution processible fluorescent dendrimers named PVCt1, PVCt2 and PVCt3 have been designed and synthesized by using 4,4′-distyryl-1,1′-biphenylene as the core and oligocarbazole as the dendron. When the dendron generation grows, the conjugation extension is limited due to the enhanced torsion between core and dendron, and simultaneously the intermolecular interactions can be weakened owing to the dendron encapsulation. As a result, a considerable hypsochromic shift is observed for both the photoluminescence and electroluminescence spectra in nondoped solid states, and the corresponding CIE coordinates move from (0.16, 0.21) of PVCt1 to (0.16, 0.15) of PVCt2 and (0.16, 0.10) of PVCt3. Moreover, compared with the sky-blue PVCt1 (0.82%), the nondoped device based on PVCt3 emits a deep-blue light with an improved external quantum efficiency of 2.81%. These results indicate that the tuning of carbazole-dendron generation can lead to deep-blue distyrylarylene-based fluorescent dendrimers used for efficient nondoped OLEDs.

以4,4'-二苯乙烯基-1,1'-联亚苯基为核，低聚咔唑为树枝状分子，设计合成了一系列溶液可加工的荧光树枝状聚合物，分别为PVCt1，PVCt2和PVCt3。当树突生成增长时，由于核心和树突之间的扭曲增强，共轭扩展受到限制，同时由于树突封装，分子间的相互作用可能会减弱。结果，在未掺杂的固态下，对于光致发光和电致发光光谱都观察到相当大的七色位移，并且相应的CIE坐标从PVCt1的（0.16，0.21）移到PVCt2的（0.16，0.15）和（0.16，0.10） PVCt3。此外，与天蓝色的PVCt1（0.82％）相比，基于PVCt3的非掺杂器件发出深蓝色光，外部量子效率提高了2.81％。这些结果表明，咔唑-树枝状分子的生成可导致用于有效非掺杂OLED的深蓝色基于二苯乙烯基的荧光树枝状聚合物。