https://scholars.lib.ntu.edu.tw/handle/123456789/607045
標題: | High-efficiency and low roll-off deep-blue OLEDs enabled by thermally activated delayed fluorescence emitter with preferred horizontal dipole orientation | 作者: | Hua T Liu Y.-C Huang C.-W Li N Zhou C Huang Z Cao X Wu C.-C Yang C. CHUNG-CHIH WU |
關鍵字: | Efficiency roll-off;Horizontal dipole orientation;Organic light-emitting diodes;Reverse intersystem crossing;Thermally activated delayed fluorescence;Fluorescence;Luminance;Organic light emitting diodes (OLED);Quantum efficiency;Quenching;Supercomputers;Dipole orientation;External quantum efficiency;Higher efficiency;Horizontal dipoles;Intersystem crossing;Photoluminescence quantum yields;Thermally activated delayed fluorescences;Efficiency | 公開日期: | 2022 | 卷: | 433 | 來源出版物: | Chemical Engineering Journal | 摘要: | Highly efficient blue thermally activated delayed fluorescence (TADF) materials with high horizontal dipole orientation (Θ//) remain a big challenge due to the concentration quenching effects and serious efficiency roll-offs in their corresponding organic light-emitting diodes (OLEDs). We herein report two novel TADF compounds, namely 2TDBA-SBA and TDBA-SBA, which were facilely synthesized by utilizing a rigid oxygen-bridged cyclized triarylboron-based unit (TDBA) as the acceptor and a spiro acridine (SBA) as the donor. Benefiting from the rigid and planar skeleton of the acceptor and the linear molecular shape, high Θ//s and photoluminescence quantum yields (PLQYs) of ? 90% were achieved. Significantly, TDBA-SBA exhibited excellent TADF properties with a short delayed fluorescence lifetime of only 684 ns and narrow full-width at half-maximum (FWHM) of 44 nm in solution state, accompanied by the high PLQYs of over 80% at high doping concentrations, manifesting the alleviated exciton quenching effects. Consequently, OLEDs based on TDBA-SBA achieved a high maximum external quantum efficiency (EQE) of 29.3% and a maximum brightness of 27663 cd cm?2. Importantly, an EQE over 20% was realized even at the high brightness of 10000 cd cm?2, signifying a small efficiency roll-off. ? 2021 Elsevier B.V. |
URI: | https://www.scopus.com/inward/record.uri?eid=2-s2.0-85120997089&doi=10.1016%2fj.cej.2021.133598&partnerID=40&md5=80708735bb893fa3e592c08f26a43054 https://scholars.lib.ntu.edu.tw/handle/123456789/607045 |
ISSN: | 13858947 | DOI: | 10.1016/j.cej.2021.133598 |
顯示於: | 電機工程學系 |
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