Multifunctional blue AIE emitters for efficient organic light emitting devices with low efficiency roll-off

Abstract

Blue organic light-emitting diodes (OLEDs) have gained tremendous attraction owing to their promising potential for flat-panel display technologies and lighting application. To make the OLEDs more useful, efficient materials are highly desired. Herein, two novel multifunctional sky-blue emitters, TPE-m-PCzI and TPE-m-TPAI, have been developed with the integration of imidazole, carbazole, triphenyl amine and tetraphenylethene groups. These materials show high photoluminescence quantum yields. Aggregation-induced emission (AIE) behavior, thermal stability and glass transition temperatures of these materials are also examined. Non-doped OLEDs fabricated employing these materials as emitters exhibit sky-blue electroluminescence and demonstrate high efficiencies of 2.22% (4.56 cd/A, 3.15 lm/W) and 3.1% (5.74 cd/A, 3.31 lm/W) for TPE-m-PCzI and TPE-m-TPAI. High performance of TPE-m-TPAI based device shows a bright prospect of imidazole and AIEgen integration to prepare efficient fluorescent materials for OLED devices.