ACTA

Highly Efficient Blue LECs Using Charged Iridium Complexes

K. Wongkhan^a, U. Mahanitipong^a, M. Srikaew^a, Y. Tantirunggrotchai^b, S. Sahasithiwat^c, R. Jitchati^a
^aDepartment of Chemistry, Faculty of Science,Ubon Ratchathani University, Ubon Ratchathani Province, 34190, Thailand
^bNational Metal and Materials Technology Center, 114 Thailand Science Park, Pahol-yothin Rd., Klong 1, Khlong Luang, Pathumthani 12120, Thailand
^cDepartment of Chemistry, Faculty of Science and Technology, Thammasat University, Pathumthani, 12120 Thailand

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Two heteroleptic charged iridium (III) species comprising two cyclometallating ligands and a neutral diimine ligand were synthesized and characterized, namely [(3,4,7,8-tetramethyl-1,10-phenanthroline-N-N')-bis-(2-(2,4-difluorophenyl)-5-(trifluoromethyl)pyridine-C⁶',N)-iridium (III)]hexafluorophosphate (UM01) and [(3,4,7,8-tetramethyl-1,10-phenanthroline-N-N')-bis-(2-(2',4'-difluoro-phenyl)-1H-pyrazole-C⁶',N)-iridium (III)]hexafluorophosphate (UM02). Both complexes were used as the blue emitter in OLED and LEC devices. We found that the optimized structure is ITO/PEDOT:PSS/complex:BMIMPF₆(1:1)/Al. The UM01 gave a current efficiency of 1.14 cd A^-1, whereas the UM02 shows a better CIE coordination at 0.19, 0.40.

DOI: 10.12693/APhysPolA.127.1109
PACS numbers: 85.60.Bt; 85.60.Jb