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Syntheses, photophysics, and application of iridium(III) phosphorescent emitters for highly efficient, long-life organic light-emitting diodes.
| Content Provider | Semantic Scholar |
|---|---|
| Author | Lee, Tsang-Chi Chang, Chiung-Fang Chiu, Yuan-Chieh Chan, Tzu-Ying Cheng, Yi-Ming Lai, Chin-Hung Chou, Pi-Tai Lee, Gene-Hsiang Chien, Chen-Han Shu, Chingfong Leonhardt, Jens |
| Copyright Year | 2009 |
| Abstract | Rational design and synthesis of Ir(III) complexes (1-3) bearing two cyclometalated ligands (C--N) and one 2-(diphenylphosphino)phenolate chelate (P--O) as well as the corresponding Ir(III) derivatives (4-6) with only one (C--N) ligand and two P--O chelates are reported, where (C--NH)=phenylpyridine (ppyH), 1-phenylisoquinoline (piqH), and 4-phenylquinazoline (nazoH). Single crystal X-ray diffraction studies of 3 reveal a distorted octahedral coordination geometry, in which two nazo ligands adopt an eclipsed configuration, with the third P--O ligand located trans to the phenyl group of both nazo ligands, confirming the general skeletal pattern for 1-3. In sharp contrast, complex 4 reveals a trans-disposition for the PPh2 groups, along with the phenolate groups residing opposite the unique cyclometalated ppy ligand, which is the representative structure for 4-6. These Ir(III) complexes exhibit green-to-red photoluminescence with moderate to high quantum efficiencies in the degassed fluid state and bright emission in the solid state. For 1-6, the resolved emission spectroscopy and relaxation dynamics are well rationalized by the computational approach. OLEDs fabricated using 12 wt. % of 3 doped in CBP and with BCP as hole blocking material, give bright electroluminescence with lambda(max)=628 nm and CIE(xy) coordinates (0.65, 0.34). The turn-on voltage is 3.2 V, while the current efficiency and the power efficiency reach 11.2 cd A(-1) and 4.5 lm W(-1) at 20 mA cm(-2). The maximum efficiency reaches 14.7 cd A(-1)and 6.8 lm W(-1) upon switching to TPBI as hole blocking material. For evaluating device lifespan, the tested device incorporating CuPc as a passivation layer, 3 doped in CTP as an emitting layer, and BAlq as hole blocking material, shows a remarkably long lifetime up to 36,000 h at an initial luminance of 500 cd m(-2). |
| File Format | PDF HTM / HTML |
| DOI | 10.1002/asia.200800468 |
| PubMed reference number | 19294729 |
| Journal | Medline |
| Volume Number | 4 |
| Issue Number | 5 |
| Alternate Webpage(s) | https://ir.nctu.edu.tw/bitstream/11536/7816/1/000266382700013.pdf |
| Alternate Webpage(s) | https://doi.org/10.1002/asia.200800468 |
| Journal | Chemistry, an Asian journal |
| Language | English |
| Access Restriction | Open |
| Content Type | Text |
| Resource Type | Article |
