• Bulletin of the Korean Chemical Society
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• v.22 no.3
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• pp.259-260
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• 2001

• Bulletin of the Korean Chemical Society
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• v.32 no.1
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• pp.122-126
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• 2011

A new phosphorescent cyclometalated heteroleptic iridium (III) complex with an ancillary ligand of 4-azacrownpicolinate was prepared and its metal ion selective phosphorescent chemosensing behavior was investigated. The new iridium (III) complex exhibits notable phosphorescence quenching for Hg2+ in aqueous 50% acetonitrile solution with respect to the selective phosphorescent detection of various metal ions including $Li^+,Na^+,K^+,Cs^+,Mg^{2+},Ca^{2+},Ba^{2+},Fe^{2+},Ni^{2+},Cu^{2+},Zn^{2+},Ag^+,Pb^{2+},Cd^{2+},Cr^{2+},Cr^{3+}$ and $Hg^{2+}$. The phosphorescence quenching for $Hg^{2+}$ increased linearly with increasing concentration of $Hg^{2+}$ in the range of $10{\mu}M-700{\mu}M$ even in the presence of other metal ions, except for $Cu^{2+}$. Consequently, the new iridium (III) complex has the potential to be utilized for the determination of parts per million levels of $Hg^{2+}$ in aqueous acetonitrile media.

• Bulletin of the Korean Chemical Society
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• v.8 no.1
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• pp.27-30
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• 1987

Photocycloaddition of 1,4,5,8-tetraazaphenanthrene to olefins proceeds through a biradical triplet-state intermediate as proven by the photoproduct stereochemistry, quantum yield measurements, sensitization, quenching, and fluorescence and phosphorescence quenching studies.

• Proceedings of the Optical Society of Korea Conference
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• 2002.11a
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• pp.244-245
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• 2002

• 한국정보디스플레이학회:학술대회논문집
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• 2005.07b
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• pp.1133-1137
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• 2005

In this paper, a renovated approach in the fabrication of red organic light-emitting diodes (OLEDs) is described. The hard-to-control doping process required for dopant-based red OLEDs can be avoided due to the novel red fluorophores that are not concentration quenching in solid state. Doping is in general a must for phosphorescence OLEDs because of the triplet-triplet annihilation, a common problem for phosphorophore dopants. However, we have recently found that extraordinary red iridium complex showing relatively short emission lifetime render the non-doped phosphorescence red OLED possible.

• Bulletin of the Korean Chemical Society
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• v.17 no.1
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• pp.56-60
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• 1996

The pressure saturation effect on the phosphorescence decay rates of the $^3B_1$ State of $SO_2$ has been reinvestigated by the laser induced phosphorescence method in pure $SO_2$. We have attempted to fit the pressure dependence of the phosphorescence decay rates using the radiationless transition model by introducing different coupling constants for each vibrational level ofthe 3B1 state. The experimental decay rates can be fitted well, when the coupling constants for the (0,0,0), (0,1,0) and (0,2,0) levels of the $^3B_1$ state are $7.2\;{\times}\;10^{-4}$, $2.2\;{\times}\;10^{-3}$ and $5.9\;{\times}\;10^{-3}\;cm^{-1}$, respectively.

• Bulletin of the Korean Chemical Society
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• v.32 no.11
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• pp.4125-4128
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• 2011

• Bulletin of the Korean Chemical Society
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• v.33 no.4
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• pp.1367-1370
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• 2012

• Journal of the Microelectronics and Packaging Society
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• v.18 no.4
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• pp.79-83
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• 2011

White phosphorescence polymer light emitting diodes (WPhPLEDs) with a glass/ITO/PEDOT:PSS/PFO:$Ir(ppy)_3$:MDMO-PPV/TPBI/LiF/Al structure were fabricated to investigate the effects of $Ir(ppy)_3$ doping concentrations on the optical and electrical properties of the devices. PFO, $Ir(ppy)_3$ and MDMO-PPV conjugated polymers as host and guest materials in the emission layer were spin coated at various concentrations of $Ir(ppy)_3$ ranging from 0.0 to 20.0 vol.%. As the concentration of $Ir(ppy)_3$ increased from 5.0 to 20.0 vol.%, the luminance and current efficiency values of the devices decreased clearly, which are attributable to the quenching effect at a high doping concentration. The maximum luminance and current density were 2850 $cd/m^2$ and 741 $mA/cm^2$, respectively for a WPhPLED with an $Ir(ppy)_3$ concentration of 5.0 vol.%. The CIE color coordinates were about x=0.33 and y=0.34 at 11V, showing a good white color.

• Bulletin of the Korean Chemical Society
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• v.33 no.10
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• pp.3465-3468
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• 2012