11.2: Novel Fluorene‐Based Blue Emitters for High Performance OLEDs

Abstract

Abstract High performance new blue‐emitting host‐dopant systems, which consist of pyrene‐substituted fluorene hosts such as DPYFL01 and diarylamino‐substituted origo(fluorenylene)s represented by BDT3FL as dopants, have been developed. The new host material, DPYFL01 showed high electron‐mobility with 1×10 −3 cm 2 /Vs. A device using DPYFL01 demonstrated blue emission (CIE: x, y = 0.15–0.16, 0.20–0.21) with high power efficiency of 4.5 lm/W at 200 cd/m 2 . The use of 20% BDT3FL in DPYFL01 resulted in deep‐blue emission (CIE: 0.15, 0.15) while keeping high power efficiency of 4.6 lm/W at 3.1 V. The device‐structure optimization together with the use of an additional host, C‐H01 afforded deep‐blue emission (CIE: 0.15, 0.14) and higher power efficiency of 4.9 lm/W and external quantum efficiency of 3.9 % at 4.3 mA/cm 2 with 200 cd/m 2 . Lifetime of the optimized device using 10 % BDT3FL was estimated to be over 10,000 hour at an initial luminance of 200 cd/m 2 .