lr(III)-Based Phosphors with Bipyrazolate Ancillaries; Rational Design, Photophysics, and Applications in Organic Light-Emitting Diodes

• Published in: Inorganic chemistry Vol. 54; no. 22; pp. 10811 - 10821
• Main Authors: Liao, Jia-Ling, Chi, Yun, Sie, Zong-Ting, Ku, Chia-Hao, Chang, Chih-Hao, Fox, Mark A, Low, Paul J, Tseng, Meu-Rurng, Lee, Gene-Hsiang
• Format: Journal Article
• Language: English
• Published: 16.11.2015
• Subjects: Chelating; Devices; Emittance; Ligands; Luminance; Organic light emitting diodes; Phosphors; Power efficiency
• DOI: 10.1021/acs.inorgchem.5b01835
• ISSN: 0020-1669

A series of three charge-neutral Ir(III) complexes bearing both neutral chelating ligands 4, 4'di-t-butyl-2, 2'bipyridine (dtbbpy) and mono-anionic cyclometalated ligands derived from 2-phenylpyridine (ppyH), together with either two mono-anionic ligands or a single dianionic chelate derived from 5, 5'di(trifluoromethyl)3, 3'bipyrazole (bipzH[sub 2]) or 5,5'(1-methylethylidene)-bis-(-3-trifluoromethyl-1H-pyrazole ) (mepzH[sub 2]), was successfully synthesized. Organic light emitting diodes were successfully fabricated. A double emitting layer design was adopted in the device architecture using Ir(III) metal complexes 3 and 4, attaining peak external quantum efficiencies, luminance efficiencies, and power efficiencies of 18.1% and 16.6%, respectively.