Effect of aromatic diamines as a cathode interface layer

The cathode interface layer (CIL) was investigated using aromatic diamine derivatives. The organic electroluminescent (EL) device with Ag cathode and CIL of Cz-TPD (4,4′-biscarbazolyl(9)-biphenyl) showed good EL characteristics comparable to a conventional MgAg device and also an improved storage stability. X-ray reflectivity measurement suggested that the rough structure of the Cz-TPD layer lowered the electron injection barrier at the Ag interface.