Syntheses and characterization of 6,6′-diaryl-9,9′-dialkyl[3,3′]bicarbazoles as materials for electroluminescent devices

摘要

Electro-active materials containing 6,6′-diaryl-substituted [3,3′]bicarbazole core were synthesized by multistep synthetic rote and characterized. The derivatives were examined by differential scanning cal-orimetry and demonstrated formation of amorphous materials with rather high glass transition temperatures. The synthesized compounds have been tested as hole transporting layers in simple OLED devices with Alq_3 as the emitter/electron transporting layer. The green devices containing hole transporting films of diphenyl-9,9′-diethyl-[3,3′]bicarbazole exhibited the best overall performance (turn-on voltage: 3.5 V, maximum photometric efficiency: 4.2 cd/A, maximum brightness: ～12,200 cd/m~2).