Novel yellow phosphorescent iridium complexes with dibenzothiophene-S, S-dioxide-based cyclometalated ligand for white polymer light-emitting diodes. (December 2018)

• Record Type: Journal Article
• Authors: Liang, Aihui; Luo, Ming; Liu, Yusheng; Wang, Han; Wang, Zhiping; Zheng, Xiaoyan; Cao, Tian; Liu, Dewang; Zhang, Yong; Huang, Fei
• Is Part Of: Dyes and pigments. Volume 159(2018)
• Page Start: 637
• Page End: 645
• Publication Date: 2018-12
• Subjects: Polymer light-emitting diode -- Electrophosphorescence -- Iridium complexes -- Dibenzothiophene-S, S-dioxide -- Carbazole; Dyes and dyeing -- Periodicals; Pigments -- Periodicals; 667.2
• DOI: 10.1016/j.dyepig.2018.07.019
• Languages: English
• ISSNs: 0143-7208

Abstract

Abstract: We have designed and synthesized two novel yellow phosphorescent iridium complexes using dibenzothiophene-S, S-dioxide-based cyclometalated ligand for the first time, which are capable of producing highly efficient yellow and white polymer light-emitting devices (PLEDs). The resulted iridium complexes display good thermal stability and high photoluminescence quantum yields. Both yellow and white PLEDs are fabricated with an identical single-emission-layer configuration of ITO/PEDOT:PSS/emission layer (EML)/CsF/Al. For the yellow phosphorescent PLEDs based on ( p -CzFSOPy)2 IrPic, the best device performances with a peak luminous efficiency (LE) of 13.3 cd/A and a peak external quantum efficiency (EQE) of 5.3% are achieved. More importantly, the two-element WPLEDs containing iridium (III)bis (2-(4, 6-difluorophenyl)-pyridinato-N, C 2′ ) picolinate (FIrpic) as blue and ( p -CzFSOPy)2 IrPic as yellow phosphors doped into a PVK:OXD- 7 matrix at an appropriate ratio exhibited a maximum LE of 19.2 cd/A, a maximum EQE of 9.6%, an extremely high luminance of 18717 cd/m 2 and Commission Internationale de L'Eclairage (CIE) coordinate of (0.317, 0.448). Moreover, at a luminance for practical application of 1000 cd/m 2, the LE still remains as high as 19.0 cd/A, with a very slight decrease. Graphical abstract: Two novel yellow phosphorescent iridium complexes with dibenzothiophene-S, S-dioxide-based cyclometalated ligand are obtained for the first time. Both highly efficient yellow and white PLEDs are fabricated with a simple single-emission-layer configuration. Image 1 Highlights: Iridium complexes with dibenzothiophene-S, S-dioxide-based ligand are obtained. Both iridium complexes display good thermal stability and high Ф P . Both yellow and white PLEDs are fabricated with a single-emission-layer configuration. The WPLEDs based on ( p -CzFSOPy)2 IrPic exhibited a highest LE of 19.2 cd A −1 .