High-efficiency and long-lifetime deep-blue organic light-emitting diode with a maximum external quantum efficiency of 20.6% and CIEy of 0.04

• Published in: Dyes and pigments 2022-09, Vol.205, p.110548, Article 110548
• Main Authors: Hu, Suhao, Tian, Yuhe, Lin, Yang, Shi, Wei, Pang, Yudong, Pan, Saihu, Wei, Bin
• Format: Article
• Language: English
• Subjects: CIE; Deep-blue; EQE; Lifetime; Organic light-emitting diodes
• ISSN: 0143-7208; 1873-3743
• DOI: 10.1016/j.dyepig.2022.110548

We synthesized a diphenylamine modified pyrene derivative, 4,9-diisopropyl-N,N,N′,N′-tetrakis-(4-methyl-biphenyl-3-yl)-pyrene-1,6-diamine (DITBDAP), and successfully applied it to deep-blue organic light-emitting diodes (OLEDs). The DITBDAP-based top-emitting OLED was featured by a high maximum external quantum efficiency (EQEmax) of 20.6%, an extremely low CIEy (Commission International de L'Eclairage coordinates) of 0.04, a narrow full-width at half maximum of 16 nm, and a long lifetime of 250 h. We chose 6,12-bis[6-trimethylphenyl)]amino5-trimethylphenyl)]amino] pyrene (Bmpac) as the comparison material due to its similar structure to DITBDAP. The DITBDAP-based bottom-emitting OLED showed a better performance compared to that of the Bmpac-based OLED, with the T95 lifetime (time to 95% of the initial luminance of 3000 cd m−2) of 250 h, which was more than twice that of the Bmpac-based OLED. In addition, the efficiency roll-off was extremely low at high brightness, which were 1% at 1100 cd m−2 and 5% at 3200 cd m−2. The synthesized DITBDAP has realized highly efficient and long-lifetime deep-blue OLEDs with the EQE up to 20.6% and CIEy as low as 0.04. •A synthesized 4,9-diisopropyl-N,N,N′,N′-tetrakis-(4-methyl-biphenyl-3-yl)-pyrene-1,6-diamine (DITBDAP) is reported.•The performance and lifetime of the OLED using DITBDAP as the emitting layer is significantly enhanced.•The maximum external quantum efficiency is 20.6%, and the CIEy is only 0.04.•The full-width at half maximum is narrowed down to 16 nm, and a long T95 lifetime of 250 h is achieved.