Hot‐Exciton‐Involved Dual‐Channel Stepwise Energy Transfer Enabling Efficient and Stable Blue OLEDs with Narrow Emission and High Luminance
Abstract
Abstract Marching toward next‐generation ultrahigh‐definition and high‐resolution displays, the development of high‐performance blue organic light‐emitting diodes (OLEDs) with narrow emission and high luminance is essential and requires conceptual advancements in both molecular and device design. Herein, a blue organic emitter is reported that exhibits hot‐exciton and aggregation‐induced emission characteristics, and use it as a sensitizer in the proposed triplet–triplet annihilation (TTA)‐assisted hot‐exciton‐sensitized fluorescence (HSF) device, abbreviated THSF. Results show that through dual‐channel stepwise Förster and Dexter energy transfer processes, the THSF system can simultaneously enhance exciton utilization, accelerate exciton dynamics, and reduce the concentration of triplet excitons. The smooth management of excitons makes the overall performance of the THSF device superior to the control TTA fluorescence and HSF devices. Furthermore, a high‐performance narrowband blue (CIE x,y = 0.13, 0.12) OLED is achieved using a two‐unit tandem device design, providing an excellent maximum external quantum efficiency of 18.3%, a record‐high L 90% (the luminance where the ƞ ext drops to 90% of its peak value) of ≈20 000 cd m −2 , and a long half‐lifetime at 100 cd m −2 initial luminance of ≈13 256 h. These results showcase the great potential of the THSF strategy in realizing efficient and stable blue OLEDs with narrow emission and high luminance.
Article Details
Authors (16)
Han Zhang
Jingli Lou
State Key Laboratory of Luminescent Materials and Devices, and Guangdong Provincial Key Laboratory of Luminescence from Molecular Aggregates
Kai Zhang
Xuecheng Guo
Hefei National Research Center for Physical Sciences at the Microscale School of Chemistry and Materials Science National Synchrotron Radiation Laboratory Department of Environmental Science and Engineering School of Nuclear Science and Technology University of Science and Technology of China Hefei Anhui China
Ganggang Li
Baoxi Li
State Key Laboratory of Luminescent Materials and Devices, and Guangdong Provincial Key Laboratory of Luminescence from Molecular Aggregates
Bingzhu Ma
State Key Laboratory of Luminescent Materials and Devices, and Guangdong Provincial Key Laboratory of Luminescence from Molecular Aggregates
Chenfa Xiao
State Key Laboratory of Luminescent Materials and Devices, and Guangdong Provincial Key Laboratory of Luminescence from Molecular Aggregates
Lu Liu
Yichao Chen
Dezhi Yang
State Key Laboratory of Luminescent Materials and Devices Guangdong Provincial Key Laboratory of Luminescence from Molecular Aggregates South China University of Technology Guangzhou 510640 China
Dongge Ma
Jianwei Sun
Jacky W. Y. Lam
Department of Chemistry, the Hong Kong Branch of Chinese National Engineering Research Center for Tissue Restoration and Reconstruction, Department of Chemical and Biological Engineering, State Key Laboratory of Nervous System Disorders, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong SAR 999077, China
Zhiming Wang
State Key Laboratory of Luminescent Materials and Devices, and Guangdong Provincial Key Laboratory of Luminescence from Molecular Aggregates
Ben Zhong Tang
School of Science and Engineering, Guangdong Basic Research Center of Excellence for Aggregate Science, The Chinese University of Hong Kong (Shenzhen), Longgang, Shenzhen 518172, Guangdong, P. R. China