High-Performance Nondoped Blue Delayed Fluorescence Organic Light-Emitting Diodes Featuring Low Driving Voltage and High Brightness
Research output: Journal Publications and Reviews › RGC 21 - Publication in refereed journal › peer-review
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Detail(s)
Original language | English |
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Article number | 1902508 |
Journal / Publication | Advanced Science |
Volume | 7 |
Issue number | 3 |
Online published | 27 Nov 2019 |
Publication status | Published - 5 Feb 2020 |
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DOI | DOI |
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Attachment(s) | Documents
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Link to Scopus | https://www.scopus.com/record/display.uri?eid=2-s2.0-85075722126&origin=recordpage |
Permanent Link | https://scholars.cityu.edu.hk/en/publications/publication(310a4a87-dff4-4564-8bc9-7cda4e3d3fa7).html |
Abstract
Thermally activated delayed fluorescence (TADF) provides great potential for the realization of efficient and stable organic light-emitting diodes (OLEDs). However, it is still challenging for blue TADF emitters to simultaneously achieve high efficiency, high brightness, and low Commission Internationale de l'Eclairage (CIE) y coordinate (CIEy) value. Here, the design and synthesis of two new benzonitrile-based TADF emitters (namely 2,6-di(9H-carbazol-9-yl)-3,5-bis(3,6-diphenyl-9H-carbazol-9-yl)benzonitrile (2PhCz2CzBn) and 2,6-di(9H-carbazol-9-yl)-3,5-bis(3,6-di-tert-butyl-9H-carbazol-9-yl)benzonitrile (2tCz2CzBn)) with a symmetrical and rigid heterodonor configuration are reported. The TADF OLEDs doped with both the emitters can achieve a high external quantum efficiency (EQE) over 20% and narrowband blue emission of 464 nm with a CIEy < 0.2. Moreover, the incorporation of a terminal tert-butyl group can weaken the intermolecular π–π stacking in the nondoped TADF emitter, and thus significantly suppress self-aggregation-caused emission quenching for enhanced delayed fluorescence. A peak EQE of 21.6% is realized in the 2tCz2CzBn-based nondoped device with an extremely low turn-on voltage of 2.7 V, high color stability, a high brightness over 20 000 cd m−2, a narrow full-width at half-maximum of 70 nm, and CIE color coordinates of (0.167, 0.248).
Research Area(s)
- blue emission, nondoped TADF emitters, organic light-emitting diodes, thermally activated delayed fluorescence, EXTERNAL QUANTUM EFFICIENCY, ROLL-OFF, EMITTERS, SINGLET
Citation Format(s)
High-Performance Nondoped Blue Delayed Fluorescence Organic Light-Emitting Diodes Featuring Low Driving Voltage and High Brightness. / Zou, Shi-Jie; Xie, Feng-Ming; Xie, Miao et al.
In: Advanced Science, Vol. 7, No. 3, 1902508, 05.02.2020.
In: Advanced Science, Vol. 7, No. 3, 1902508, 05.02.2020.
Research output: Journal Publications and Reviews › RGC 21 - Publication in refereed journal › peer-review
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