High‐efficiency thermally activated delayed fluorescence materials via a shamrock‐shaped design strategy to enable OLEDs with external quantum efficiency over 38%
Gaoyu Li,
Junrong Pu,
Zhan Yang,
Huangjun Deng,
Yanyan Liu,
Zhu Mao,
Juan Zhao,
Shi‐Jian Su,
Zhenguo Chi
Affiliations
Gaoyu Li
PCFM Lab GD HPPC Lab State Key Laboratory of Optoelectronic Material and Technologies Guangdong Engineering Technology Research Center for High performance Organic and Polymer Photoelectric Functional Films School of Chemistry Sun Yat‐sen University GuangzhouP. R. China
Junrong Pu
State Key Laboratory of Luminescent Materials and Devices and Institute of Polymer Optoelectronic Materials and Devices South China University of Technology GuangzhouP. R. China
Zhan Yang
PCFM Lab GD HPPC Lab State Key Laboratory of Optoelectronic Material and Technologies Guangdong Engineering Technology Research Center for High performance Organic and Polymer Photoelectric Functional Films School of Chemistry Sun Yat‐sen University GuangzhouP. R. China
Huangjun Deng
PCFM Lab GD HPPC Lab State Key Laboratory of Optoelectronic Material and Technologies Guangdong Engineering Technology Research Center for High performance Organic and Polymer Photoelectric Functional Films School of Chemistry Sun Yat‐sen University GuangzhouP. R. China
Yanyan Liu
PCFM Lab GD HPPC Lab State Key Laboratory of Optoelectronic Material and Technologies Guangdong Engineering Technology Research Center for High performance Organic and Polymer Photoelectric Functional Films School of Chemistry Sun Yat‐sen University GuangzhouP. R. China
Zhu Mao
Shenzhen Institute of Advanced Electronic Materials Shenzhen Institutes of Advanced Technology Chinese Academy of Sciences ShenzhenChina
Juan Zhao
State Key Laboratory of Optoelectronic Material and Technologies School of Materials Science and Engineering Sun Yat‐sen University GuangzhouChina
Shi‐Jian Su
State Key Laboratory of Luminescent Materials and Devices and Institute of Polymer Optoelectronic Materials and Devices South China University of Technology GuangzhouP. R. China
Zhenguo Chi
PCFM Lab GD HPPC Lab State Key Laboratory of Optoelectronic Material and Technologies Guangdong Engineering Technology Research Center for High performance Organic and Polymer Photoelectric Functional Films School of Chemistry Sun Yat‐sen University GuangzhouP. R. China
Abstract To achieve highly‐efficient organic light‐emitting diodes (OLEDs), great efforts have been devoted into constructing thermally activated delayed fluorescence (TADF) with high horizontal dipole ratios (Θ//). Here, we proposed a design strategy by integrating a rigid electron‐accepting oxygen‐bridged boron core with triple electron‐donating groups, which exhibited a “shamrock‐shape”, namely BO‐3DMAC and BO‐3DPAC. Benefiting from the rigid and large‐planar skeletons brought by shamrock‐shaped design, BO‐3DMAC and BO‐3DPAC exhibit high Θ// of 84%/70% and 93%/94% in neat/doped films, respectively, and finally furnish excellent external quantum efficiencies (EQEs) of up to 28.3% and 38.7% in 20 wt% doped OLEDs with sky‐blue emission, as well as adequate EQEs of up to 21.0% and 16.7% in nondoped OLEDs. This work unveils a promising strategy to establish high‐Θ// TADF emitters by constructing large‐planar molecular structures using shamrock‐shaped design.
