Highly thermal stable electron-transporting materials using triptycene derivatives for OLEDs

Abstract Highly thermal stable two-electron transport materials (ETMs) based on the triptycene containing phenylpyridine derivatives were designed and synthesized by Suzuki-Miyaura coupling reactions efficiently. Among them, TPP shows a high triplet energy gap (ET = 2.85 eV), high glass transition temperature (Tg = 142 °C), deep HOMO level (7.0 eV) and good electron mobility. TPP performed as ETM for the green phosphorescent OLED was achieved high external quantum efficiency (EQE) compared to that of the device with TmPyPB as ETM. Moreover, thermal stability was demonstrated after thermal annealing of the device at 100 °C for 30 min, resulting in the TPP-based device reached a high EQE of 13.6% at a luminance of 100 cd m−2, while that of TmPyPB-based device have dramatically degraded under otherwise identical conditions.