Creation of Efficient Blue Aggregation-Induced Emission Luminogens for High-Performance Nondoped Blue OLEDs and Hybrid White OLEDs
journal contributionposted on 23.04.2019, 00:00 by Yinghao Li, Zeng Xu, Xiangyu Zhu, Bin Chen, Zhiming Wang, Biao Xiao, Jacky W. Y. Lam, Zujin Zhao, Dongge Ma, Ben Zhong Tang
Organic blue luminescent materials are essential for organic light-emitting diodes (OLEDs). However, high-quality blue materials that can fulfill the requirements of OLED commercialization are much rare. Herein, two novel blue luminogens, 9-(4-(2,6-di-tert-butyl-10-(4-(1,2,2-triphenylvinyl)phenyl)anthracen-9-yl)phenyl)-9H-carbazole and 9-(4-(2,6-di-tert-butyl-10-(4-(1,2,2-triphenylvinyl)phenyl)anthracen-9-yl)1,3-di(9H-carbazol-9-yl)benzene (TPE-TADC), consisting of anthracene, tetraphenylethene, and carbazole groups are successfully prepared, and their thermal, optical, electronic, and electrochemical properties are fully investigated. They exhibit prominent aggregation-induced emission property and strong blue fluorescence at ∼455 nm in neat films. Efficient nondoped OLEDs are fabricated with these blue luminogens, providing blue electroluminescence (EL) at 451 nm (CIEx,y = 0.165, 0.141) and high EL efficiencies of 6.81 cd A–1, 6.57 lm W–1, and 5.71%. By utilizing TPE-TADC as a blue emissive layer, high-performance two-color hybrid white OLEDs are achieved, furnishing modulatable light color from pure white (CIEx,y = 0.33, 0.33) to warm white (CIEx,y = 0.44, 0.46) and excellent EL efficiencies of 56.7 cd A–1, 55.2 lm W–1, and 19.2%. More importantly, these blue and white OLEDs all display ultrahigh color and efficiency stabilities at high luminance, indicating the great potential of these blue luminogens for the application in OLED displays and white illumination.