Simultaneous high efficiency/CRI/spectral stability and low efficiency roll-off hybrid white organic light-emitting diodes via simple insertion of ultrathin red/green phosphorescent emitters in a blue exciplex. Issue 36 (1st September 2020)

• Record Type: Journal Article
• Authors: Chen, Yuwen; Wu, Yibing; Lin, Chengwei; Dai, Yanfeng; Sun, Qian; Yang, Dezhi; Qiao, Xianfeng; Ma, Dongge
• Is Part Of: Journal of materials chemistry. Volume 8:Issue 36(2020)
• Page Start: 12450
• Page End: 12456
• Publication Date: 2020-09-01
• Subjects: Materials -- Periodicals; Chemistry, Analytic -- Periodicals; Optical materials -- Research -- Periodicals; Electronics -- Materials -- Research -- Periodicals; 543.0284
• DOI: 10.1039/d0tc03053h
• Languages: English
• ISSNs: 2050-7526

Abstract

Abstract : High performance hybrid WOLEDs have been realized by precisely inserting ultrathin red/green phosphorescent layers in a blue exciplex emitter. Abstract : The simultaneous achievement of high efficiency, low efficiency roll-off, good spectral stability and a high color rendering index (CRI) is still a challenge in hybrid white organic light-emitting diodes (WOLEDs). In this paper, we strategically design a device structure by simply inserting ultrathin red/green phosphorescent emitters in a blue exciplex to efficiently utilize excitons for light emission. The resulting WOLEDs not only exhibit high efficiency and low efficiency roll-off, but also maintain a high CRI and stable spectral emission. The maximum power efficiency (PE), current efficiency (CE) and external quantum efficiency (EQE) reached 66.2 lm W −1, 50.6 cd A −1 and 21.2% and remained at 50.9 lm W −1, 45.2 cd A −1 and 18.3% at 100 cd m −2 and 34.6 lm W −1, 35.5 cd A −1 and 15.8% at 1000 cd m −2, respectively. In addition, the electroluminescence (EL) spectra were also extremely stable with a high CRI of 86 and Commission Internationale de L'Eclairage (CIE) coordinates of (0.40 ± 0.01, 0.46 ± 0.01) from 500 to 10 000 cd m −2 . The achievement of good comprehensive performance is attributed to the efficient device structure of ultrathin phosphors in the exciplex that can realize 100% exciton utilization without affecting the electrical properties.