Highly-efficient solution-processed green phosphorescent organic light-emitting diodes with reduced efficiency roll-off using ternary blend hosts. Issue 36 (1st August 2019)

• Record Type: Journal Article
• Authors: Zhang, Jianhua; Guan, Yuxin; Yang, Jiali; Hua, Wenqiang; Wang, Shuanglong; Ling, Zhitian; Lian, Hong; Liao, Yingjie; Lan, Weixia; Wei, Bin; Wong, Wai-Yeung
• Is Part Of: Journal of materials chemistry. Volume 7:Issue 36(2019)
• Page Start: 11109
• Page End: 11117
• Publication Date: 2019-08-01
• Subjects: Materials -- Periodicals; Chemistry, Analytic -- Periodicals; Optical materials -- Research -- Periodicals; Electronics -- Materials -- Research -- Periodicals; 543.0284
• DOI: 10.1039/c9tc02701g
• Languages: English
• ISSNs: 2050-7526

Abstract

Abstract : We have investigated the effect of various materials mCP DpAn-5BzAc poly(9-vinylcarbazole) and TCTA as the hosts on the performance of solution-processed green phosphorescent organic light-emitting diodes (PhOLEDs). Abstract : We have investigated the effect of various materials 1, 3-bis(carbazol-9-yl)benzene (mCP), 10-(4-(5, 5-dimethylbenzofuro[3, 2- c ]acridin-13(5 H )-yl)phenyl)-10-phenylanthracen-9(10 H )-one (DpAn-5BzAc), poly(9-vinylcarbazole) and 4, 4′, 4′′-tris( N -carbazolyl)-triphenylamine (TCTA) as the hosts on the performance of solution-processed green phosphorescent organic light-emitting diodes (PhOLEDs). Compared with the corresponding single and binary host systems, the device with the ternary blend hosts (mCP:DpAn-5BzAc:TCTA) blended with bis(2-phenylpyridine)iridium(iii ) acetylacetonate as a green dopant is highly efficient with the following performance parameters: a maximum brightness of 40 320 cd m −2 and a maximum current efficiency (CE) of 40.9 cd A −1 with the Commission Internationale de L'Eclairage coordinates of (0.30, 0.63). More importantly, the PhOLED device has an extremely low efficiency roll-off: at the brightness values of 1000 and 5000 cd m −2, its CEs are close, being 40.6 and 36.5 cd A −1, with the corresponding efficiency roll-off of only 0.7% and 10.8%, respectively. The superior electroluminescence performance for ternary blend host-based green PhOLEDs was attributed to the enhanced charge carrier balance, improved structural order in the film as verified by using the grazing-incidence small-angle scattering technique, along with excellent multi-component miscibility, which has a dramatic influence on the morphology of the emissive layer and the final device performance. These results demonstrate the great potential of the multi-hosts in solution-processed organic optoelectronic devices.