Highly-efficient solution-processed green phosphorescent organic light-emitting diodes with reduced efficiency roll-off using ternary blend hosts

Jianhua Zhang, Yuxin Guan, Jiali Yang, Wenqiang Hua, Shuanglong Wang, Zhitian Ling, Hong Lian, Yingjie Liao, Weixia Lan, Bin Wei, Wai Yeung Wong (Corresponding Author)

Research output: Journal article publicationJournal articleAcademic researchpeer-review

8 Citations (Scopus)

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(5H)-yl)phenyl)-10-phenylanthracen-9(10H)-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 40320 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.

Original languageEnglish
Pages (from-to)11109-11117
Number of pages9
JournalJournal of Materials Chemistry C
Volume7
Issue number36
DOIs
Publication statusPublished - 1 Jan 2019

ASJC Scopus subject areas

  • Chemistry(all)
  • Materials Chemistry

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