Manipulating the benzenyl π-bridge of bisanthracene derivatives (BDs) for highly efficient deep-blue OLED emitters with CIEy = 0.06

Abstract

Due to the difficulty in balancing high efficiency and high color purity, the development of blue luminescent materials remains a significant challenge in the fields of commercial full-color organic light emitting devices (OLEDs) and solid-state lighting. Herein, we report four deep-blue fluorescent emitters with non-donor–acceptor (non-DA)-type and DA-type structures, namely BD1-DMP (non-DA-type), BD1-DOP (non-DA-type), BD3-DMP (DA-type), and BD3-DOP (DA-type), in which molecular manipulation strategies are applied to modify the benzenyl π-bridge of bisanthracene derivatives (BDs) with methyl or methoxy substituents. The incorporation of methyl or methoxy groups results in a large distorted configuration, reducing the degree of molecular conjugation, and the emission peak is limited in the deep-blue region, exhibiting high photoluminescence efficiency. The doped OLED device based on BD1-DMP exhibits deep-blue emission (λ_em,max = 415 nm), with a maximum external quantum efficiency (EQE) of 7.07% and Commission Internationale de l’Eclairage (CIE) coordinates of (0.15, 0.06), meeting high-definition television (HDTV) display standards. BD1-DMP as the host material and DSA-Ph doped sky-blue devices were further constructed, with a maximum EQE, current efficiency (CE), and luminance of 6.60%, 11.17 cd A⁻¹, and 16 410 cd m⁻², respectively. It is worth noting that there is only 1.5% EQE roll-off at 1000 cd m⁻². These excellent properties ensure that newly developed BDs can not only be used as doping materials to construct high-efficiency and high-standard deep-blue OLEDs but also as the host material to construct high-efficiency and extremely low roll-off sky-blue devices, which provide more selectivity for the development of deep-blue OLED emitters.