New Oxazoline- and Thiazoline-Containing Heteroleptic Iridium(III) Complexes for Highly-Efficient Phosphorescent Organic Light-Emitting Devices (PhOLEDs): Colour Tuning by Varying the Electroluminescence Bandwidth

Chao, Kai; Shao, Kuizhan; Peng, Tai; Zhu, Dongxia; Wang, Yue; Liu, Yu; Sua, Zhongmin; Bryce, Martin R.

Abstract

Two new homologous phosphorescent iridium complexes, bis-(2-phenylpyridine)(2-(2′-hydroxyphenyl)-2-oxazoline)iridium(III) [(ppy)2Ir(oz)] (1) and bis-(2-phenylpyridine)(2-(2′-hydroxyphenyl)-2-thiazoline)iridium(III) [(ppy)2Ir(thoz)] (2), have been obtained in good yields and characterized by single-crystal X-ray diffraction, cyclic voltammetry, photoluminescence and electroluminescence studies, and by time-dependent density functional theory (TD-DFT) calculations. Using the two complexes, which differ only by the heteroatom (O or S) substitution at the same site in the ancillary ligand, as the emitter, doped in a 4,4′-bis(N-carbazolyl)biphenyl (CBP) host, gave phosphorescent organic light-emitting diodes (PhOLEDs) with very efficient green and yellow emission, respectively. The turn-on voltages for both devices are low (3.5–3.7 V). The green-emitting (ppy)2Ir(oz) – based device has a maximum brightness of 61560 cd m−2 (at 16 V); maximum luminance efficiency of 66.2 cd A−1, 17.1% external quantum efficiency, 54 lm W−1 power efficiency and CIE coordinates of (0.35, 0.61) at a brightness of 10000 cd m−2. For the yellow-emitting (ppy)2Ir(thoz)-based device with a wide full spectral width at half maximum (FWHM) of 110 nm, the corresponding values are 21350 cd m−2 (at 14.5 V); 27.0 cd A−1, 8.5%, 18.0 lm W−1 and CIE coordinates of (0.46, 0.50). Colour tuning is primarily a consequence of the significantly wider emission bandwidth of complex 2 compared to complex 1.

Citation

Chao, K., Shao, K., Peng, T., Zhu, D., Wang, Y., Liu, Y., …Bryce, M. R. (2013). New Oxazoline- and Thiazoline-Containing Heteroleptic Iridium(III) Complexes for Highly-Efficient Phosphorescent Organic Light-Emitting Devices (PhOLEDs): Colour Tuning by Varying the Electroluminescence Bandwidth. Journal of Materials Chemistry C Materials for optical and electronic devices, 1(41), 6800-6806. https://doi.org/10.1039/c3tc31463d

• Journal Article Type: Article
• Publication Date: Nov 7, 2013
• Deposit Date: Nov 24, 2014
• Publicly Available Date: Nov 26, 2014
• Journal: Journal of Materials Chemistry C
• Print ISSN: 2050-7526
• Electronic ISSN: 2050-7534
• Publisher: Royal Society of Chemistry
• Peer Reviewed: Peer Reviewed
• Volume: 1
• Issue: 41
• Pages: 6800-6806
• DOI: https://doi.org/10.1039/c3tc31463d
• Public URL: https://durham-repository.worktribe.com/output/1449905