Narrowband blue emission with insensitivity to the doping concentration from an oxygen-bridged triarylboron-based TADF emitter: nondoped OLEDs with a high external quantum efficiency up to 21.4

Jianmei Han; Zhongyan Huang; Jingsheng Miao; Yuntao Qiu; Ziyang Xie; Chuluo Yang

doi:10.1039/d2sc00329e

Narrowband blue emission with insensitivity to the doping concentration from an oxygen-bridged triarylboron-based TADF emitter: nondoped OLEDs with a high external quantum efficiency up to 21.4

Chem Sci. 2022 Feb 21;13(12):3402-3408. doi: 10.1039/d2sc00329e. eCollection 2022 Mar 24.

Authors

Jianmei Han^{1

2}, Zhongyan Huang¹, Jingsheng Miao¹, Yuntao Qiu¹, Ziyang Xie¹, Chuluo Yang¹

Affiliations

¹ Shenzhen Key Laboratory of Polymer Science and Technology, College of Materials Science and Engineering, Shenzhen University Shenzhen 518060 P. R. China clyang@szu.edu.cn.
² College of Physics and Optoelectronic Engineering, Shenzhen University Shenzhen 518060 P. R. China.

Abstract

Blue thermally activated delayed fluorescence (TADF) emitters that can simultaneously achieve narrowband emission and high efficiency in nondoped organic light-emitting diodes (OLEDs) remain a big challenge. Herein, we successfully design and synthesize two blue TADF emitters by directly incorporating carbazole fragments into an oxygen-bridged triarylboron acceptor. Depending on the linking mode, the two emitters show significantly different photophysical properties. Benefitting from the bulky steric hindrance between the acceptor and terminal pendants, the blue emitter TDBA-Cz exhibited a high photoluminescence quantum yield (PLQY) of 88% in neat films and narrowband emission. The corresponding non-doped blue device exhibited a maximum external quantum efficiency (EQE) of 21.4%, with a full width at half maximum (FWHM) of only 45 nm. This compound is the first blue TADF emitter that can concurrently achieve narrow bandwidth and high electroluminescence (EL) efficiency in nondoped blue TADF-OLEDs.