A linear deep-blue bipolar fluorescent material with the CIEy < 0.065 serving as the emitter and host for high-performance monochromatic and hybrid white OLEDs

Abstract

In this work, a novel linear deep-blue hybrid local and charge transfer fluorophore (P2MPC) with good thermal stability, balanced bipolar transporting properties, a high horizontal dipole ratio of 86.5%, and a triplet state energy over 2.4 eV is developed for constructing high efficiency and low efficiency roll-off monochromatic and hybrid white organic light emitting diodes (OLEDs). P2MPC can not only serve as a neat emitter to develop non-doped OLEDs, realizing a Commission Internationale de L’Eclairage (CIE) coordinate of (0.157, 0.064) and a high external quantum efficiency (EQE) of 7.15%, but also act as a universal host to sensitize green, yellow and red phosphors, achieving high efficiency and low roll-off phosphorescent OLEDs. More significantly, high-performance complementary-color and three-color hybrid white OLEDs with forward-viewing EQEs and power efficiencies of 24.63%/82.43 lm W⁻¹ and 22.65%/55.60 lm W⁻¹ are achieved using P2MPC as the emitter and host. By weakening the electron-trapping effect on dopant sites, white OLEDs exhibit excellent spectral stability with the CIE coordinates varying from (0.003, 0.002) and (0.004, 0.008) in the range of 1000 to 10 000 cd m⁻². Such high efficiencies achieved based on P2MPC can provide a new insight for designing high-performance non-doped deep-blue OLEDs and hybrid white OLEDs.