Emergence of Flexible White Organic Light-Emitting Diodes

Flexible white organic light-emitting diodes (FWOLEDs) have considerable potential to meet the rapidly growing requirements of display and lighting commercialization. To achieve high-performance FWOLEDs, (i) the selection of effective flexible substrates, (ii) the use of transparent conducting electrodes, (iii) the introduction of efficient device architectures, and iv) the exploitation of advanced outcoupling techniques are necessary. In this review, recent state-of-the-art strategies to develop FWOLEDs have been summarized. Firstly, the fundamental concepts of FWOLEDs have been described. Then, the primary approaches to realize FWOLEDs have been introduced. Particularly, the effects of flexible substrates, conducting electrodes, device architectures, and outcoupling techniques in FWOLEDs have been comprehensively highlighted. Finally, issues and ways to further enhance the performance of FWOLEDs have been briefly clarified.