Pure Hydrocarbon Materials as Highly Efficient Host for White Phosphorescent Organic Light-Emitting Diodes: A New Molecular Design Approach
Fan-Cheng Kong1,#, Yuan-Lan Zhang1,#, Cassandre Quinton2,#, Nemo McIntosh3,#, Sheng-Yi Yang1, Joëlle Rault-Berthelot2, Fabien Lucas2, Clément Brouillac2, Olivier Jeannin2, Jérôme Cornil3, Zuo-Quan Jiang1,*, Liang-Sheng Liao1,4,*,and Cyril Poriel2,*
1Institute of Functional Nano & Soft Materials (FUNSOM), Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices, Soochow University, Suzhou, Jiangsu 215123, China.
2Univ Rennes, CNRS, ISCR- UMR 6226, 35000 Rennes, France.
3Laboratory for Chemistry of Novel Materials, University of Mons, 7000 Mons, Belgium
4Macau Institute of Materials Science and Engineering, Macau University of Science and Technology, Macao, 999078, China.
To date, all efficient host materials reported for phosphorescent OLEDs (PhOLEDs) are constructed with heteroatoms, which have a crucial role in the device performance. However, it has been shown in recent years that the heteroatoms not only increase the design complexity but can also be involved in the instability of the PhOLED, which is nowadays the most important obstacle to overcome. Herein, we design pure aromatic hydrocarbon materials (PHC) as very efficient hosts in high-performance white and blue PhOLEDs. With EQE of 27.7%, the PHC-based white PhOLEDs display similar efficiency as the best reported with heteroatom-based hosts. Incorporated as a host in a blue PhOLED, which are still the weakest links of the technology, a very high EQE of 25.6% is reached, surpassing, for the first time, the barrier of 25% for a PHC and FIrpic blue emitter. This performance shows that the PHC strategy represents an effective alternative for the future development of the OLED industry.