High-performance blue electroluminescent devices based on 2-(4-biphenylyl)-5-(4-carbazole-9-yl)phenyl-1,3,4-oxadiazole

An electron transporting moiety (1,3,4-oxadiazole) and a hole transporting moiety (carbazole) were combined to create 2-(4-biphenylyl)-5-(4-carbazole-9-yl)phenyl-1,3,4-oxadiazole (CzOxa), a three layer device with a configuration of ITO/TPD(50 nm)/CzOxa(40 nm)/AlQ(40 nm)/Mg0.9Ag0.1(200 nm)/Ag(80 nm) which exhibited a blue emission peak at ∼470 nm (x = 0.14, y = 0.19) with a maximum luminance of 26200 cd m−2 at a drive voltage of 15 V and a maximum luminous efficiency of 2.25 lm W−1.