Red Phosphorescent Emitters Research Articles

Synthesis, Characterization, and Photophysical Properties of Iridium Complexes with an 8-Phenylquinoline Framework. The First Six-Membered Chelated Iridium Complexes for Electroluminance

A series of six-membered chelated iridium complexes bearing an 8-phenylquinoline framework have been prepared and characterized with an X-ray diffraction study. The photophysical properties of these complexes were examined with appropriate spectroscopic methods. The results, in combination with ab initio approaches, led us to clearly assign various electronic transition states. One salient feature for these red complexes is the appearance of a dual strong absorption band around 425−500 nm, which incorporates a state mixing between 1MLCT and π−π* manifolds. These complexes show deep red phosphorescent emissions (650−680 nm), with short lifetimes of 1.7−3.0 μs and moderate quantum yields of 0.05−0.11 in deaerated CH3CN. The electroluminance performance of these species shows a promising perspective in the OLED display. One representative, Ir[8-(3,5-difluorophenyl)quinoline]2(acac) (4c), shows a ηext value of 2.04% at J = 20 mA/cm2 and the maximum brightness is 3427 cd/m2 (x = 0.68, y = 0.32) with a full width at half-maximum of only 60 nm at 16 V, demonstrating the first six-membered chelated iridium complexes to suit applications in OLED devices.

Highly Efficient Red Phosphorescent Osmium(II) Complexes for OLED Applications

The nonionic, red-emitting complexes [Os(fppz)2L2] (L = PPh2Me (1), PPhMe2 (2)) and [Os(bptz)2L2] (L = PPh2Me (3)) were synthesized, showing highly intense red phosphorescent emission in CH2Cl2 solution at λmax 617, 632, and 649 nm, respectively. The electroluminescent properties of these compounds on OLEDs showed promising device efficiencies required for future OLED applications.

Synthesis of a high-efficiency red phosphorescent emitter for organic light-emitting diodes

Download options Please wait... Article information DOI https://doi.org/10.1039/B313843G Article type Paper Submitted 31 Oct 2003 Accepted 24 Dec 2003 First published 11 Feb 2004 Download Citation J. Mater. Chem., 2004,14, 947-950 BibTex EndNote MEDLINE ProCite ReferenceManager RefWorks RIS Permissions Request permissions Synthesis of a high-efficiency red phosphorescent emitter for organic light-emitting diodes C. Yang, C. Tai and I. Sun, J. Mater. Chem., 2004, 14, 947 DOI: 10.1039/B313843G To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page. If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given. If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page. Read more about how to correctly acknowledge RSC content. Search articles by author Cheng-Hsien Yang Chia-Cheng Tai I-Wen Sun

High efficiency and low power consumption in active matrix organic light emitting diodes

Abstract Phosphorescent full color 2.2 inch quarter common intermediate format (QCIF) active matrix organic light emitting diodes (AMOLED) have been developed for mobile phone application. Red and green phosphorescent emitters have been adopted as light emitting components and the efficiency of the AMOLED as measured was enhanced up to 10.9 cd/A at a white brightness of 100 cd/m2. The power consumption of the AMOLED was reduced below 200 mW due to high efficiency and low driving voltage.

Divalent osmium complexes: synthesis, characterization, strong red phosphorescence, and electrophosphorescence.

We report new divalent osmium complexes that feature strong red metal-to-ligand-charge-transfer (MLCT) phosphorescence and electrophosphorescence. The general formula of the complexes is Os(II)(N-N)(2)L-L, where N-N is either a bipyridine or a phenanthroline and L-L is either a phosphine or an arsine. New polypyridyl ligands synthesized are 4,4'-di(biphenyl)-2,2'-bipyridine (15) and 4,4'-di(diphenyl ether)-2,2'-bipyridine (16), and the 1,10-phenanthroline derivatives synthesized are 4,7-bis(p-methoxyphenyl)-1,10-phenanthroline (17), 4,7-bis(p-bromophenyl)-1,10-phenanthroline (18), 4,7-bis(4'-phenoxybiphen-4-yl)-1,10-phenanthroline (19), and 4,7-bis(4-naphth-2-ylphenyl)-1,10-phenanthroline (20). 4,4'-Diphenyl-2,2'-bipyridine (21) and 4,7-diphenyl-1,10-phenanthroline (22) were also used in these studies. Strong pi-acid ligands used were 1,2-bis(diphenylarseno)ethane (23), cis-1,2-bis(diphenylphosphino)ethylene (24), and cis-1,2-vinylenebis(diphenylarsine) (25). Ligand 25 is used for the first time in these types of luminescent osmium complexes. These compounds feature strong MLCT absorption bands in the visible region and strong red phosphorescent emission ranging from 611 to 651 nm, with quantum efficiency up to 45% in ethanol solution at room temperature. Red organic light-emitting diodes (OLEDs) were successfully fabricated by doping the Os(II) complexes into blend of poly(N-vinylcarbazole) (PVK) and 2-tert-butylphenyl-5-biphenyl-1,3,4-oxadiazole (PBD). Brightness over 1400 cd/m(2) for a double-layer device has been reached, with a turn-on voltage of 8 V. The maximum external quantum efficiency was 0.64%. Commission Internationale de l'Eclairage (CIE) chromaticity coordinates (x, y) of the red electrophosphorescence from the complexes are (0.65, 0.34), which indicates pure red emission.