High-efficiency deep-blue organic light-emitting diodes using dual-emitting layer

High-efficiency deep-blue organic light-emitting diodes (OLED) using novel deep-blue host and dopant based on dual-emitting layer (D-EML) system which compose of 2-methyl-9,10-di(2-naphthyl)anthracene and 4′-(dinaphthalen-2-yl)-1,1′-binaphthyl as hosts and 9-N-phenylcarbazole-3-vinyl-p-terphenyl as a dopant exhibits good confinement of holes and electrons and broad recombination zone. The optimized deep-blue OLED showed a maximum luminance of 5780 cd/m2 at 10.5 V, maximum external quantum efficiency of 4.68%, a maximum current efficiency of 5.22 cd/A, and Commission Internationale d’Eclairage coordinates of (0.15, 0.09). This deep-blue OLED with D-EML also showed higher efficiency by a factor of 1.4 and 1.3 at 1 mA/cm2 than the control devices with single-EML using MADN and DNBN, respectively.