Efficient bifunctional materials based on pyrene- and triphenylamine-functionalized dendrimers for electroluminescent devices

Abstract

© The Royal Society of Chemistry. To realize highly efficient bifunctional blue-light emitting and hole-transporting materials for OLEDs, a series of pyrene- and triphenylamine-peripheral functionalized carbazole dendrimers, namely G1PYR, G2PYR, G1TPA and G2TPA, were designed, synthesized and characterized. Especially, G2PYR having four pyrene units substituted on the 2ndgeneration carbazole dendritic scaffold exhibited a strong blue emission with high Tgamorphous and good film-forming properties. Simple structured blue OLED (λEL= 463 nm) using G2PYR as emissive layer and Alq3-based green OLED (λEL= 512 nm) using G2PYR as hole-transporting layer with high luminance efficiencies (η) and low turn-on voltages (Von) of 5.89 cd A-1and 3.1 V, and 5.15 cd A-1and 2.6 V were attained, respectively.