Controlling Singlet–Triplet Energy Splitting for Deep‐Blue Thermally Activated Delayed Fluorescence Emitters

• Published in: Angewandte Chemie International Edition Vol. 56; no. 6; pp. 1571 - 1575
• Main Authors: Cui, Lin‐Song, Nomura, Hiroko, Geng, Yan, Kim, Jong Uk, Nakanotani, Hajime, Adachi, Chihaya
• Format: Journal Article
• Language: English
• Published: WEINHEIM Wiley 01.02.2017; Wiley Subscription Services, Inc
• Edition: International ed. in English
• Subjects: Architecture; carbazole; Chemistry; Chemistry, Multidisciplinary; Emission; Emissions; Emitters; Energy; Fluorescence; organic electronics; organic light-emitting diodes; Physical Sciences; Science & Technology; singlet–triplet splitting; Splitting; COMPLEXES; organic electronics; singlet-triplet splitting; GREEN; organic light-emitting diodes; ELECTROLUMINESCENCE; LIGHT-EMITTING-DIODES; MOLECULAR DESIGN; HOSTS; PHOSPHORESCENT; EXTERNAL QUANTUM EFFICIENCY; fluorescence; DEVICES; carbazole; ROLL-OFF
• ISSN: 1433-7851; 1521-3773
• DOI: 10.1002/anie.201609459

The development of efficient metal‐free organic emitters with thermally activated delayed fluorescence (TADF) properties for deep‐blue emission is still challenging. A new family of deep‐blue TADF emitters based on a donor–acceptor architecture has been developed. The electronic interaction between donor and acceptor plays a key role in the TADF mechanism. Deep‐blue OLEDs fabricated with these TADF emitters achieved high external quantum efficiencies over 19.2 % with CIE coordinates of (0.148, 0.098). Deep blue emission: An internal quantum efficiency (IQE) of almost 100 % was achieved in organic light‐emitting diodes by a rational molecular design strategy. The organic light‐emitting diodes showed deep‐blue thermally activated delayed fluorescence.