Difluoroboron locking tactic enhances photo- and electroluminescence of TADF emitter. (August 2021)

• Record Type: Journal Article
• Authors: Zhan, Lisi; Ning, Weimin; Gong, Shaolong; Xie, Guohua; Yang, Chuluo
• Is Part Of: Dyes and pigments. Volume 192(2021)
• Publication Date: 2021-08
• Subjects: Organic light-emitting diode -- Thermally activated delayed fluorescence -- Difluoroboron compound -- Red emitters -- Electron acceptor; Dyes and dyeing -- Periodicals; Pigments -- Periodicals; 667.2
• DOI: 10.1016/j.dyepig.2021.109392
• Languages: English
• ISSNs: 0143-7208

Abstract

Abstract: Luminescent organoboron materials have attracted considerable interests in the field of organic light-emitting diodes (OLEDs). However, their applications are limited by their complicated synthetic routes. Herein, a simple and efficient difluoroboron locking tactic was employed to enhance molecular rigidity and electron accepting strength of thermally activated delayed fluorescence emitters. With this tactic, the resulting difluoroboron compound, MBF, exhibited more rigid configuration and higher acceptor strength than the reference emitter of MPA, resulting in nearly three times higher photoluminescence quantum yield in doped film and a bathochromic emission shift of 91 nm in dilute toluene solution. In comparison with the MPA-based reference device, the MBF-based OLED rendered six times higher maximum external quantum efficiency accompanied with an electroluminescence peak at 630 nm. Graphical abstract: The difluoroboron locking tactic was used to construct a near-infrared TADF emitter MBF. The solution-processed device based on the organoboron-locked emitter MBF exhibited 6 times higher EQE with respect to the reference ESIPT emitter MPA, featured an EL emission at 630 nm and a broad full-width-at-half-maximum of 138 nm at a doping concentration of 10 wt%. Image 1 Highlights: Difluoroboron locking tactic was adopted to construct an organoboron-based TADF emitter. The organoboron-based emitter achieved 3 times higher PLQY than the reference emitter. Non-doped device based on the difuoroboron locked emitter depicted an ELpeak at 690 nm.