Red Phosphorescent Bis-Cyclometalated Iridium Complexes with Fluorine-, Phenyl-, and Fluorophenyl-Substituted 2-Arylquinoline Ligands

• Published in: Chemistry : a European journal Vol. 22; no. 12; pp. 4036 - 4045
• Main Authors: Kim, Jwajin, Lee, Kum Hee, Lee, Seok Jae, Lee, Ho Won, Kim, Young Kwan, Kim, Young Sik, Yoon, Seung Soo
• Format: Journal Article
• Language: English
• Published: WEINHEIM Blackwell Publishing Ltd 14.03.2016; Wiley; Wiley Subscription Services, Inc
• Subjects: 2-arylquinoline ligands; 8-Hydroxyquinoline; Aluminum; Biphenyl; Chemistry; Chemistry, Multidisciplinary; Devices; Emission; Fluorine; Hydroxyquinoline; Indium tin oxide; Indium tin oxides; Iridium; Iridium compounds; Ligands; Lithium; Luminance; OLEDs; Phosphorescence; Physical Sciences; Quantum efficiency; red electroluminescence; Science & Technology; Tin; IR(III) COMPLEXES; ELECTROCHEMISTRY; STATES; 2-arylquinoline ligands; phosphorescence; OLEDs; iridium; LIGHT-EMITTING-DIODES; ELECTROPHOSPHORESCENT PROPERTIES; PHOTOPHYSICS; EMISSION; red electroluminescence; DERIVATIVES
• ISSN: 0947-6539; 1521-3765
• DOI: 10.1002/chem.201504392

Red phosphorescent iridium(III) complexes based on fluorine‐, phenyl‐, and fluorophenyl‐substituted 2‐arylquinoline ligands were designed and synthesized. To investigate their electrophosphorescent properties, devices were fabricated with the following structure: indium tin oxide (ITO)/4,4′,4′′‐tris[2‐naphthyl(phenyl)amino]triphenylamine (2‐TNATA)/4,4′‐bis[N‐(1‐naphthyl)‐N‐phenylamino]biphenyl (NPB)/4,4′‐bis(N‐carbazolyl)‐1,1′‐biphenyl (CBP): 8 % iridium (III) complexes/bathocuproine (BCP)/tris(8‐hydroxyquinolinato)aluminum (Alq3)/8‐hydroxyquinoline lithium (Liq)/Al. All devices, which use these materials showed efficient red emissions. In particular, a device exhibited a saturated red emission with a maximum luminance, external quantum efficiency, and luminous efficiency of 14200 cd m−2, 8.44 %, and 6.58 cd A−1 at 20 mA cm−2, respectively. The CIE (x, y) coordinates of this device are (0.67, 0.33) at 12.0 V. Dopant in red: Nine iridium complexes with fluorine‐, phenyl‐, and fluorophenyl‐substituted 2‐arylquinoline ligands for red phosphorescence organic light‐emitting diodes were prepared. A device based on (2,4‐pentanedionato)bis[2‐(9,9‐dimethyl‐9 H‐fluoren‐2‐yl)‐5‐(4‐fluorophenyl)quinolinyl]iridium(III) showed an efficient deep red emission with an external quantum efficiency of 8.44 % at 20 mA cm−2.