A novel luminophor and host polymer from fluorene-carbazole derivatives for preparing solution-processed non-doped blue and closed-white light devices

A novel blue light emitting polymer was designed and synthesized via alternative conjugated 9,9-dioctylfluorene and 9-(6-(9H-carbazol-9-yl)hexyl)-9H-carbazole, named PF2Cz. It exhibited high thermal stability, good film morphology and strong deep-blue emission peaks at 408 and 429 nm in film. The triplet energy level of PF2Cz (E-T = 2.30 eV) was also improved. Non-doped and doped devices were both prepared by solution process to characterize the electroluminescent (EL) properties of PF2Cz. In non doped devices, PF2Cz acted as blue emitter which exhibited a Commission Internation de L'Eclairage (CIE) coordinate of (0.164, 0.102) and a external quantum efficiency (EQE) values of 1.28%. Moreover, the doped phosphorescent devices utilized PF2Cz as host material obtained a closed-white light emission with a content of 1 dopant. All these results indicated that the fluorene-carbazole derivatives could be a promising molecular design strategy for the synthesis of blue light and host organic semiconductors. (C) 2018 Elsevier Ltd. All rights reserved.