Conjugated Asymmetric Donor-Substituted 1,3,5-Triazines: New Host Materials for Blue Phosphorescent Organic Light-Emitting Diodes
摘要:
AbstractConjugated asymmetric donor‐substituted 1,3,5‐triazines (ADTs) have been synthesized by nucleophilic substitution of organolithium catalyzed by [Pd(PPh3)4]. Theoretical and experimental investigations show that ADTs possess high solubility and thermostability, high fluorescent quantum yield (35 %), low HOMO (−6.0 eV) and LUMO (−2.8 eV), and high triplet energy (ET, 3.0 eV) according to the different substitution pattern of triazine. The application as host materials for blue PHOLEDs yielded a maximum current efficiency of 20.9 cd A−1, a maximum external quantum efficiency of 9.8 %, and a brightness of 9671 cd m−2 at 5.4 V, making ADTs good candidates for optoelectronic devices.
An organic electroluminescence device according to an embodiment includes a first electrode, a hole transport region disposed on the first electrode, an exciton diffusion layer disposed on the hole transport region and including a first host represented by Formula 1, an emission layer disposed on the exciton diffusion layer and including a second host, a third host, and a phosphorescent dopant, an electron transport region disposed on the emission layer, and a second electrode disposed on the electron transport region. The organic electroluminescence device exhibits high efficiency and a long service life.