Speakers

Professor Hui XU received his PhD degree in Organic Chemistry from Fudan University under the supervision of Professor Wei Huang. Then he joined the Key Laboratory of Functional Inorganic Material Chemistry of Heilongjiang University in 2006 and promoted full professor in 2011. Form 2011 to 2013, he worked in Professor Xiaogang Liu's group of National University of Singapore as a postdoctoral researcher. From 2018 to 2019, he was supported by Humboldt Fellowship for Experienced Researchers and worked in Professor Meerholz group in Cologne University. He is dean of school of chemistry and materials science and deputy director of the Key Laboratory of Functional Inorganic Material Chemistry (Chinese Ministry of Education). He was elected in Young Scholar Project of Changjiang Scholars Program of China and Longjiang Scholars Program of Heilongjiang Province. He has published more than 100 peer-reviewed SCI papers in Nat. Photon., Sci. Adv., Nat. Commun., Chem, J. Am. Chem. Soc., Angew. Chem. Int. Ed., Adv. Mater., and so on, with citations over 4000, and awarded the first class of Heilongjiang province science and technology award. His current research focuses on phosphorus-containing functional materials, including small molecules, complexes and polymers, for optoelectronic applications, which encompasses chemistry, material science and device physics. The classical chemical techniques are used as the underlying approach for assembling phosphorus-containing building blocks into integrated systems and exploring new applications, e.g. organic light-emitting diodes, photodetectors and solar cells. In particular, he is interested in utilizing electronic and spatial effects of phosphorus-based functional groups to control excited-state characteristics and intermolecular interactions and discovering new scientific phenomena.

Thermally Activated Delayed Fluorescence White OLEDs 

Abstract

White thermally activated delayed fluorescence (TADF) materials and devices emerge rapidly.^[1] TADF materials based on organic molecular systems endow the devices with the merits of low cost, sustainability and environmental friendliness and so on. Therefore, white TADF diodes have the huge potential in daily lighting applications. However, the large polarity, serious quenching and marked dependence on device structures of TADF molecules induce the big challenges in developing high-performance TADF white OLEDs (WOLED). To avert these issues, most of TADF WOLEDs adopted complicated device structures of multiple hosts and emitting layers (EML).

Based on our previous works about blue TADF materials and devices, in recent years, we further realized high-performance single-EML TADF WOLEDs, through optimizing excite-state characteristics and aggregation behaviors of hosts and blue TADF molecules, and tuning carrier and exciton allocation processes between blue and yellow dopant.^[2] The maximum external quantum efficiencies were beyond 20%, accompanied by effectively suppressed efficiency roll-offs, reaching the state-of-the-art levels of white phosphorescent OLEDs.

Keywords：TADF, OLED, Exciton Allocation, Energy Transfer, White, Lighting

References

1. H. Uoyama, K. Goushi, K. Shizu, H. Nomura, C. Adachi, Nature 2012, 492, 234-238.
2. a) J. Zhang, D. Ding, Y. Wei, F. Han, H. Xu, W. Huang, Adv. Mater. 2016, 28, 479-485; b) D. Ding, Z. Wang, C. Li, J. Zhang, C. Duan, Y. Wei, H. Xu, Adv. Mater. 2020, 32, 1906950; c) C. Han, R. Du, H. Xu, S. Han, P. Ma, J. Bian, C. Duan, Y. Wei, M. Sun, X. Liu, W. Huang, Nat Commun 2021, 12, 3640.