Organic light-emitting diodes based on new oxadiazole and pyrazoline derivatives

The bilayer heterojunction devices were fabricated successfully by using a novel oxadiazole derivative: 2, 2'-(2,5-thiophenediyl) bis (5-(4-methyl) ph enyl-1,3,4-oxadiazole) (T-OXD) as the electron-transporting layer (ETL) and a pyrazoline derivative: 1-phenyl-3-(dimethylamino)styryl)-5-(p-(dimethyla mino) phenyl)pyrazoline (PDP) as the light-emitting layer and the hole-tran sporting layer. The emission at 500 nm was derived from PDP layer. In compa rison with the bilayer device of tris (8-hydroxyquinoline) aluminum (Alq) a s the ETL, the luminous efficiency of the PDP/T-OXD heterojunction device w as enhanced by 10(4) times.