New transport layers for highly efficient organic electroluminescence devices

Multiheterostructure electroluminescence (EL) devices with blue emission co lor based on parahexaphenyl (PHP) as the emitting layer and various new org anic materials as hole and/or electron transport layers (HTL, ETL) were fab ricated to improve the EL efficiency. We present new ETLs, which were prepa red via different metal-catalyzed coupling reactions of brominated educts i n high yields. Utilizing these new organic materials enables us to obtain h igh performance of blue PHP EL devices with low threshold fields (0.3 MV/cm ) and high external EL quantum efficiencies up to 3.4%.