Highly Efficient Red Phosphorescent OLEDs with Simple Device Structure

Abstract

We report high efficiency red phosphorescent OLEDs with a simple organic bi-layered structure. A host material bis(10-hydroxybenzo[h] quinolinato)beryllium complex (Bebq2) having a good electron transporting and energy transfer characteristics and a good hole injection and transport material N,N′-di(4-(N,N′-diphenyl-amino)phenyl)-N,N′-diphenylbenzidine (DNTPD) lead to the fabrication of simplified high efficiency device. The driving voltage value of 3.5 V to reach luminance of 1000 cd/m2 is reported. The maximum current- and power-efficiency values of 9.38 cd/A and 11.72 lm/W with real true red color of (0.67, 0.32) are demonstrated.