Efficient red organic LEDs via the combination of an exciplex host and micro-cavity. (18th May 2022)

• Record Type: Journal Article
• Authors: Li, Jiao-Yang; Wang, Ya-Kun; Zhou, Jun-Gui; He, Wei; Dong, Xiao-Hao; Zhang, Chuan; Shi, Xiao-Bo; Lia, Liang-Sheng; Fung, Man-Keung
• Is Part Of: Materials chemistry frontiers. Volume 6:Number 12(2022)
• Page Start: 1623
• Page End: 1629
• Publication Date: 2022-05-18
• Subjects: Materials science -- Periodicals; Chemistry -- Periodicals; 540
• DOI: 10.1039/d2qm00203e
• Languages: English
• ISSNs: 2052-1529

Abstract

Abstract : We report a current efficiency of 99.7 cd A −1 for a red OLED with an electroluminescence (EL) peak at 604 nm (full width at half maximum of 32 nm). Abstract : Exploring exciplexes as the host in organic light-emitting diodes (OLEDs) has attracted extensive attention because of the low driving voltage and high efficiency. However, conventional exciplex-host-based bottom-emission still shows undesirable efficiencies, especially in the red emission channels, due to energy gap law. We here propose exciplex-host-based top-emitting devices to achieve breakthrough efficiency in red light-emitting devices. We optimize the exciplex hosts to maximize energy transfer to the emitting dyes and the cavity length and reflective electrodes to achieve efficient red organic LEDs. We report a current efficiency of 99.7 cd A −1 for a red OLED with an electroluminescence (EL) peak at 604 nm (full width at half maximum of 32 nm); these efficiencies are the best in red OLEDs, especially with a narrow EL spectrum. This work offers a new strategy to achieve high efficiency and high color-purity LEDs simultaneously.