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1596090 
Journal Article 
Two novel orange cationic iridium(III) complexes with multifunctional ancillary ligands used for polymer light-emitting diodes 
Tang, H; Li, Y; Zhao, B; Yang, Wei; Wu, H; Cao, Y 
2012 
1 
Organic Electronics
ISSN: 1566-1199 
13 
12 
3211-3219 
WOS:000311681600060 
Two novel orange cationic iridium complexes [(npy)(2)Ir(o phen)]PF6 and [(npy)(2)Ir(c-phen)] PF6 were synthesized. Hnpy: 2-(naphthalen-1-yl) pyridine; o phen: a 1,10-phenanthroline derivative containing an electron-transporting functional group of
2,5-diphenyl-1,3,4-oxadiazole and a crystallization-resistant tert-butyl functional group; c-
phen: a 1,10-phenanthroline derivative containing a hole-transporting functional group of
carbazole and a crystallization-resistant 2-ethylhexyl functional group. Both of them are
amorphous and possess high thermal stability with 5% weight-reduction temperatures (Delta T-5%)
of 386 degrees C and 383 degrees C, and glass-transition temperatures (T-g) of 267 degrees C and
195 degrees C respectively. They were used as phosphorescent dopants in polymer light-emitting
diodes (PLEDs) fabricated by solution-processed technology with configuration of
ITO/PEDOT:PSS/PVK:PBD:iridium complex/TPBI/CsF/Al. At the optimal doping concentration of 2.0 wt
%, the corresponding PLEDs exhibited the maximum current efficiencies of 9.1 cd A(-1) and 10.0 cd
A(-1), the maximum external quantum efficiencies of 6.5% and 7.1%, and the maximum luminance of
2314 cd m(-2) and 3157 cd m(-2) respectively, with the same CIE coordinates of (0.57, 0.40). The
results indicate that cationic iridium complexes are promising candidates for PLED applications
when they are designed reasonably. (C) 2012 Elsevier B.V. All rights reserved. 
Cationic iridium complex; Polymer light-emitting diode; Oxadiazole; Carbazole