Bright, efficient, and stable pure-green hyperfluorescent organic light-emitting diodes by judicious molecular design

• Published in: Nature communications 2024-04, Vol.15 (1), p.3174-3174, Article 3174
• Main Authors: Lee, Yi-Ting, Chan, Chin-Yiu, Matsuno, Nanami, Uemura, Shigetada, Oda, Susumu, Kondo, Masakazu, Weerasinghe, Rangani Wathsala, Hu, Yanmei, Lestanto, Gerardus N. Iswara, Tsuchiya, Youichi, Li, Yufang, Hatakeyama, Takuji, Adachi, Chihaya
• Format: Article
• Language: English
• Subjects: 119/118; 140/131; 140/58; 639/301/1005; 639/624/1020/1091; Conjugation; Display devices; Emitters; Fluorescence; High definition; Humanities and Social Sciences; Light; Light emitting diodes; multidisciplinary; Organic light emitting diodes; Quantum efficiency; Resonance; Science; Science (multidisciplinary)
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-024-47482-3

To fulfill ultra-high-definition display, efficient and bright green organic light-emitting diodes with Commission Internationale de l’Éclairage y-coordinate ≥ 0.7 are required. Although there are some preceding reports of highly efficient devices based on pure-green multi-resonance emitters, the efficiency rolloff and device stabilities for those pure-green devices are still unsatisfactory. Herein, we report the rational design of two pure-green multi-resonance emitters for achieving highly stable and efficient pure-green devices with CIE x,y s that are close to the NTSC and BT. 2020 standards. In this study, our thermally activated delayed fluorescence OLEDs based on two pure-green multi-resonance emitters result in CIE y up to 0.74. In hyperfluorescent device architecture, the CIE x s further meet the x-coordinate requirements, i.e., NTSC (0.21) and BT. 2020 (0.17), while keeping their CIE y s ~ 0.7. Most importantly, hyperfluorescent devices display the high maximum external quantum efficiencies of over 25% and maximum luminance of over 10 5  cd m −2 with suppressed rolloffs (external quantum efficiency of ~20% at 10 4  cd m −2 ) and long device stabilities with LT 95 s of ~ 600 h. The device performance of pure-green hyperfluorescent organic light-emitting diodes remains unsatisfactory. Here, the authors report multi-resonance emitters with extended π−conjugation or increased donor strength, resulting in bright, efficient and stable pure-green hyperfluorescent devices.