Highly efficient greenish blue-emitting organic diodes based on pyrene derivatives

We report the synthesis of pyrene derivatives as the light emissive layer for highly efficient organic electroluminescence (EL) diodes. Multilayer devices were fabricated with pyrene derivatives (ITO/NPB (50 nm)/blue material (30 nm)/BCP (10 nm)/Alq₃ (30 nm)/LiF (1 nm)/Al). By using 1,1′-dipyrene (DP) and 1,4-dipyrenyl benzene (DPB), the devices produced the blue EL emissions with 1931 Commission International de L’Eclairage coordinates of (x=0.21, y=0.35) and (x=0.19, y=0.25), respectively. The device with DPB shows a maximum brightness of 42,445 cd/m² at 400 mA/cm² and the luminance efficiency of 8.57 cd/A and 5.18 lm/W at 20 mA/cm².