Thermally Activated Delayed Fluorescence with Nanosecond Emission Lifetimes and Minor Concentration Quenching: Achieving High-Performance Nondoped and Doped Blue OLEDs

Shao-Jie Wu; Xi-Feng Fu; Dong-Hai Zhang; Yu-Fu Sun; Xin Lu; Fu-Lin Lin; Lingyi Meng; Xu-Lin Chen; Can-Zhong Lu

doi:10.1002/adma.202401724

Thermally Activated Delayed Fluorescence with Nanosecond Emission Lifetimes and Minor Concentration Quenching: Achieving High-Performance Nondoped and Doped Blue OLEDs

Adv Mater. 2024 Apr 4:e2401724. doi: 10.1002/adma.202401724. Online ahead of print.

Authors

Shao-Jie Wu^{1

2

3}, Xi-Feng Fu^{1

2

3}, Dong-Hai Zhang^{1

2}, Yu-Fu Sun^{1

2}, Xin Lu^{1

2}, Fu-Lin Lin^{1

2}, Lingyi Meng^{1

2}, Xu-Lin Chen^{1

2

3

4}, Can-Zhong Lu^{1

2

3

4}

Affiliations

¹ State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian, 350002, China.
² Xiamen Key Laboratory of Rare Earth Photoelectric Functional Materials, Xiamen Institute of Rare Earth Materials, Haixi Institutes, Chinese Academy of Sciences, Xiamen, Fujian, 361021, China.
³ College of Chemistry, Fuzhou University, Fuzhou, Fujian, 350108, China.
⁴ Fujian Science and Technology Innovation Laboratory for Optoelectronic Information of China, Fuzhou, Fujian, 350108, China.

PMID: 38575151
DOI: 10.1002/adma.202401724

Abstract

Simultaneously achieving a high photoluminescence quantum yield (PLQY), ultrashort exciton lifetime, and suppressed concentration quenching in thermally activated delayed fluorescence (TADF) materials is desirable yet challenging. Here, a novel acceptor-donor-acceptor type TADF emitter, namely, 2BO-sQA, wherein two oxygen-bridged triarylboron (BO) acceptors are arranged with cofacial alignment and positioned nearly orthogonal to the rigid dispirofluorene-quinolinoacridine (sQA) donor is reported. This molecular design enables the compound to achieve highly efficient (PLQYs up to 99%) and short-lived (nanosecond-scale) blue TADF with effectively suppressed concentration quenching in films. Consequently, the doped organic light-emitting diodes (OLEDs) base on 2BO-sQA achieve exceptional electroluminescence performance across a broad range of doping concentrations, maintaining maximum external quantum efficiencies (EQEs) at over 30% for doping concentrations ranging from 10 to 70 wt%. Remarkably, the nondoped blue OLED achieves a record-high maximum EQE of 26.6% with a small efficiency roll-off of 14.0% at 1000 candelas per square meter. By using 2BO-sQA as the sensitizer for the multiresonance TADF emitter ν-DABNA, TADF-sensitized fluorescence OLEDs achieve high-efficiency deep-blue emission. These results demonstrate the feasibility of this molecular design in developing TADF emitters with high efficiency, ultrashort exciton lifetime, and minimal concentration quenching.

Keywords: blue emission; concentration quenching; emission lifetime; organic light‐emitting diodes; thermally activated delayed fluorescence.

Abstract

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