Iminodibenzyl-substituted distyrylarylenes as dopants for blue and white organic light-emitting devices

A series of highly efficient blue materials based on iminodibenzyl-substituted distyrylarylene (IDB-series) fluorescent dyes using the concept of steric-compression have been designed and synthesized by means of a rigidized and over-sized ring. The steric-compression effect can shorten the effective conjugation length (chromophore) of the molecule and the added phenyl moiety in the core can alleviate the propensity for molecular aggregation. These materials also possess high glass transition temperature over 100 °C. The blue IDB-Ph device achieved a maximum external quantum efficiency of 4.8% with a Commission Internationale de l’Eclairage (CIEx,y) coordinate of (0.16, 0.28). When applied in two-element white OLED system, the IDB-Ph doped device achieved a luminance efficiency of 11.0 cd/A with a CIEx,y color coordinate of (0.29, 0.36).