Efficient red light phosphorescence emission in simple bi-layered structure organic devices with fluorescent host-phosphorescent guest system

摘要

Highly efficient red phosphorescent devices comprising a simple bi-layered structure using tris(1-phenylisoquilioline)iridium (Ir(piq)(3)) doped in a narrow band-gap fluorescent host material, bis(10-hydroxybenzo [h] quinolinato)beryllium complex (Bebq(2)) are reported. The driving voltage to reach 1000 cd/m(2) is 3.5 V in Bebq(2):Ir(piq)(3) red phosphorescent device. With a dopant concentration of as low as 4%, the current and power efficiency Values of 8.41 cd/A and 7.34 Im/W are obtained in this PHOLEDs. respectively. External quantum efficiency (EQE) of 14.5% is noticed in this red phosphorescent device, promising to high brightness applications.