High efficiency, solution-processed, red phosphorescent organic light-emitting diodes from a polymer doped with iridium complexes

• Published in: Organic electronics Vol. 10; no. 7; pp. 1412 - 1415
• Main Authors: Song, Myungkwan, Park, Jin Su, Kim, Chul-Hyun, Im, Min Joung, Kim, Jang Soo, Gal, Yeong-Soon, Kang, Jae-Wook, Lee, Jae Wook, Jin, Sung-Ho
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01-11-2009; Elsevier
• Subjects: Applied sciences; Electronics; Exact sciences and technology; Hole transporting material; Optoelectronic devices; PhOLEDs; Phosphorescent; Red; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; Solution-process; Red; 73.50.Gr; 78.40.Me; 73.61.Ph; Solution-process; 78.60.Fi; PhOLEDs; Hole transporting material; Phosphorescent; Performance evaluation; Red light; Electroluminescence; Carbazole(vinyl) polymer; Thiophene derivative polymer; Tin oxide; Optoelectronic device; Phosphorescence; Growth from solution; Organic electronics; Polymer blends; Cathode; Hole mobility; Iridium complex; Doped materials; Polymer; Quantum yield; Indium oxide; Luminance; Organic light emitting diodes; Styrenesulfonate polymer; Iridium
• ISSN: 1566-1199; 1878-5530
• DOI: 10.1016/j.orgel.2009.07.012

High efficiency, solution-processed, red emissive phosphorescent organic light-emitting diodes (PhOLEDs) have been developed. The PhOLEDs utilize
bis[9-ethyl-3-(4-phenylquinolin-2-yl)-9H-carbazolato-
N,C
2′]iridium picolinate (Et-Cvz-PhQ)
2Ir(pic) and
bis[9-(2-(2-methoxyethoxy)ethyl)-3-(4-phenylquinolin-2-yl)-9H-carbazolato-
N,C
2′]iridium picolinate (EO-Cvz-PhQ)
2Ir(pic) in a nonconjugated polymer host of PVK that contains the electron transport material of OXD-7 and the hole transport material TPD. The electroluminescence (EL) spectra of the PhOLEDs parallel those of (Et-Cvz-PhQ)
2Ir(pic) and (EO-Cvz-PhQ)
2Ir(pic) with maxima at 608
nm and a CIE (Commission International de l’Eclairage) coordinate of (0.62, 0.38). The red emitting PhOLEDs, based on ITO/PEDOT:PSS/PVK:OXD-7:TPD:Ir complex/cathode configuration, have a maximum external quantum efficiency of 10.6% and a luminance efficiency of 17.5
cd/A. The efficiency is significantly higher than those obtained using common solution-processed red emissive PhOLEDs.