1
|
Lee YT, Chan CY, Matsuno N, Uemura S, Oda S, Kondo M, Weerasinghe RW, Hu Y, Lestanto GNI, Tsuchiya Y, Li Y, Hatakeyama T, Adachi C. Bright, efficient, and stable pure-green hyperfluorescent organic light-emitting diodes by judicious molecular design. Nat Commun 2024; 15:3174. [PMID: 38609364 PMCID: PMC11014922 DOI: 10.1038/s41467-024-47482-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2023] [Accepted: 04/02/2024] [Indexed: 04/14/2024] Open
Abstract
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 CIEx,ys 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 CIEy up to 0.74. In hyperfluorescent device architecture, the CIExs further meet the x-coordinate requirements, i.e., NTSC (0.21) and BT. 2020 (0.17), while keeping their CIEys ~ 0.7. Most importantly, hyperfluorescent devices display the high maximum external quantum efficiencies of over 25% and maximum luminance of over 105 cd m-2 with suppressed rolloffs (external quantum efficiency of ~20% at 104 cd m-2) and long device stabilities with LT95s of ~ 600 h.
Collapse
Affiliation(s)
- Yi-Ting Lee
- Center for Organic Photonics and Electronics Research (OPERA), Kyushu University, Motooka, Nishi, Fukuoka, Japan
- Department of Chemistry, Soochow University, Taipei, ROC, Taiwan
| | - Chin-Yiu Chan
- Department of Materials Science and Engineering, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong SAR, China.
- Department of Chemistry, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong SAR, China.
| | - Nanami Matsuno
- Department of Chemistry, Graduate School of Science, Kyoto University, Sakyo-ku, Kyoto, Japan
| | - Shigetada Uemura
- Department of Chemistry, Graduate School of Science, Kyoto University, Sakyo-ku, Kyoto, Japan
| | - Susumu Oda
- Department of Applied Chemistry, Graduate School of Science and Engineering, Toyo University, Kawagoe, Saitama, Japan
| | | | - Rangani Wathsala Weerasinghe
- Center for Organic Photonics and Electronics Research (OPERA), Kyushu University, Motooka, Nishi, Fukuoka, Japan
| | - Yanmei Hu
- Center for Organic Photonics and Electronics Research (OPERA), Kyushu University, Motooka, Nishi, Fukuoka, Japan
| | - Gerardus N Iswara Lestanto
- Center for Organic Photonics and Electronics Research (OPERA), Kyushu University, Motooka, Nishi, Fukuoka, Japan
| | - Youichi Tsuchiya
- Center for Organic Photonics and Electronics Research (OPERA), Kyushu University, Motooka, Nishi, Fukuoka, Japan
| | - Yufang Li
- Department of Materials Science and Engineering, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong SAR, China
- Department of Chemistry, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong SAR, China
| | - Takuji Hatakeyama
- Department of Chemistry, Graduate School of Science, Kyoto University, Sakyo-ku, Kyoto, Japan.
| | - Chihaya Adachi
- Center for Organic Photonics and Electronics Research (OPERA), Kyushu University, Motooka, Nishi, Fukuoka, Japan.
- International Institute for Carbon Neutral Energy Research (WPI-I2CNER), Kyushu University, Nishi, Fukuoka, Japan.
| |
Collapse
|
2
|
Weerasinghe RW, Madayanad Suresh S, Hall D, Matulaitis T, Slawin AMZ, Warriner S, Lee YT, Chan CY, Tsuchiya Y, Zysman-Colman E, Adachi C. A Boron, Nitrogen, and Oxygen Doped π-Extended Helical Pure Blue Multiresonant Thermally Activated Delayed Fluorescent Emitter for Organic Light Emitting Diodes That Shows Fast k RISC Without the Use of Heavy Atoms. Adv Mater 2024:e2402289. [PMID: 38581139 DOI: 10.1002/adma.202402289] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/13/2024] [Revised: 04/03/2024] [Indexed: 04/08/2024]
Abstract
Narrowband emissive multiresonant thermally activated delayed fluorescence (MR-TADF) emitters are a promising solution to achieve the current industry-targeted color standard, Rec. BT.2020-2, for blue color without using optical filters, aiming for high-efficiency organic light-emitting diodes (OLEDs). However, their long triplet lifetimes, largely affected by their slow reverse intersystem crossing rates, adversely affect device stability. In this study, a helical MR-TADF emitter (f-DOABNA) is designed and synthesized. Owing to its π-delocalized structure, f-DOABNA possesses a small singlet-triplet gap, ΔEST, and displays simultaneously an exceptionally faster reverse intersystem crossing rate constant, kRISC, of up to 2 × 106 s-1 and a very high photoluminescence quantum yield, ΦPL, of over 90% in both solution and doped films. The OLED with f-DOABNA as the emitter achieved a narrow deep-blue emission at 445 nm (full width at half-maximum of 24 nm) associated with Commission Internationale de l'Éclairage (CIE) coordinates of (0.150, 0.041), and showed a high maximum external quantum efficiency, EQEmax, of ≈20%.
Collapse
Affiliation(s)
- Rangani Wathsala Weerasinghe
- Center for Organic Photonics and Electronics Research (OPERA), Kyushu University, Motooka, Nishi, Fukuoka, 819-0395, Japan
| | - Subeesh Madayanad Suresh
- Organic Semiconductor Centre, EaStCHEM School of Chemistry, University of St Andrews, St Andrews, KY16 9ST, UK
| | - David Hall
- Organic Semiconductor Centre, EaStCHEM School of Chemistry, University of St Andrews, St Andrews, KY16 9ST, UK
| | - Tomas Matulaitis
- Organic Semiconductor Centre, EaStCHEM School of Chemistry, University of St Andrews, St Andrews, KY16 9ST, UK
| | - Alexandra M Z Slawin
- Organic Semiconductor Centre, EaStCHEM School of Chemistry, University of St Andrews, St Andrews, KY16 9ST, UK
| | - Stuart Warriner
- School of Chemistry, University of Leeds, Woodhouse Lane, Leeds, LS2 9JT, UK
| | - Yi-Ting Lee
- Center for Organic Photonics and Electronics Research (OPERA), Kyushu University, Motooka, Nishi, Fukuoka, 819-0395, Japan
| | - Chin-Yiu Chan
- Department of Materials Science and Engineering, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong, 000-000, China
- Department of Chemistry, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong, 000-000, China
| | - Youichi Tsuchiya
- Center for Organic Photonics and Electronics Research (OPERA), Kyushu University, Motooka, Nishi, Fukuoka, 819-0395, Japan
| | - Eli Zysman-Colman
- Organic Semiconductor Centre, EaStCHEM School of Chemistry, University of St Andrews, St Andrews, KY16 9ST, UK
| | - Chihaya Adachi
- Center for Organic Photonics and Electronics Research (OPERA), Kyushu University, Motooka, Nishi, Fukuoka, 819-0395, Japan
| |
Collapse
|