Solution-processed OLEDs based on a novel thermally cross-linkable host material
Tang YJ., Zhuang JY., Su WM., Zhang DY., Cui Z., Hao J.
© 2016, Science Press. All right reserved. In order to realize the high efficiency OLEDs by solution process, a cross-linkable host material, VB-CzTAZ containing carbazole and 1,2,4-triazole units was designed and synthesized. It is found that VB-CzTAZ with styryl groups can be thermally cross-linked by curing at 190℃ without any polymerization initiator. Besides the excellent thermal stability (Td:323℃) and good surface morphology, the thermally cross-linked film of VB-CzTAZ also shows excellent solvent resistances as rinsing with different solvent. For the phosphorescent OLEDs (PhOLED) incorporating VB-CzTAZ as host, the turn-on voltage is 5.1 V, the maximum luminance is 2 404 cd/m2, and the maximum current efficiency is 4.3 cd/A, respectively. It indicates that the cross-linkable host material has potential to be used for the solution-processed multilayer PhOLED.