Toward Achieving Single-Molecule White Electroluminescence from Dual Emission of Fluorescence and Phosphorescence
Hao Chen, Yihua Deng, Xiangyu Zhu, Lu Wang, Lei Lv, Xiaoxi Wu, Zijie Li, Qinqin Shi, Aidong Peng, Qian Peng, Zhigang Shuai, Zujin Zhao, Huajie Chen, Hui Huang
Abstract
White organic light-emitting diodes (WOLEDs) are of great value in daily life. However, the organic white-emissive single molecules in OLEDs are rare. Herein, we report a group of carbazolyl derivatives containing thiophene (PhCz-S), selenophene (PhCz-Se), and tellurophene (PhCz-Te). Through modulating the chalcogen atom, the promoted intersystem crossing brings room-temperature phosphorescence. Moreover, PhCz-Se exhibits Commission Internationale de l’Eclairage (CIE) coordinates of (0.30, 0.29) in OLEDs measured at 4 V, which is the first example of the single-molecule WOLEDs combined with dual emission from singlet and triplet states. Also, PhCz-Te realized WOLEDs in a single emission layer at CIE coordinates of (0.34, 0.33). The theoretical and experimental results clearly show that the adjustment of heavy atoms exerts influence on the luminescent properties, which provides a new strategy for designing single-molecule WOLEDs.