A New Class of Host Materials for Blue Phosphorescent Organic Electroluminescent Devices

摘要

We report a new class of host materials for phosphorescent iridium complexes. These materials were designed to have ambipolar character. The host materials share a 2,2'-diimidazole core and typically triarylamine or carbazole containing motifs which may give the materials electron-transporting and hole-transporting utility, respectively. We have since synthesised a new host material (MMH-001) and have applied this material in OLED devices with two different emitters; FIrpic, and our own proprietary blue Iridium emitter; MMPBD-001. The MMH-001/FIpic device has CIE_(1931) coordinates measured as (0.15, 0.34) and performance measured as 5.5 V, 27.2 cd/A, 15.6 lm/W, at 1 mA/cm~2. The MMH-001/MMPBD-001 device shows a deeper blue colour (CIE_(1931) 0.15, 0.24) and performance measured as 5.4 V, 21.0 cd/A, 12.0 lm/W, at 1 mA/cm~2.