• Proceedings of the KIEE Conference
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• 2005.07c
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• pp.1890-1892
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• 2005

Recently, high luminance and high efficiency were realized in OLEDs with multilayer structure including emitting materials such as metal-chelate complexes. New luminescent materials, [2- (2-hydroxyphenyl)-quinoline] (Zn(HPB)q), [(1,10-phenanthroline)- (8-hydroxyquinoline)] Zn(Phen)q was synthesized. Zn-Complexes have low molecular compound and thermal stability. The ionization potential(IP) and electron affinity(EA) of Zn-complexes were measured by cyclic-voltammetry(CV). The fundamental structure of the OLEDs was $ITO/{\alpha}$-NPD/Zn-Complex/Al and then we made device structure rightly in energy band gap. We using Zn(Phen)q as emitting layer and Zn(HPB)q as electron transport layer. We measured current density-voltage, luminance-voltage characteristics.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2007.11a
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• pp.436-437
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• 2007

Organic light-emitting diodes (OLEDs) were fabricated with the electron dominant complex, 4,7-diphenyl-1, 10-phenanthroline (Bphen) into the traditional electron transporting material of tris (S-hydroxyquinoline) aluminum $(Alq_3)$, neat $Alq_3$ and Bphen as electron-transporting layers (ETLs), respectively. Use of the Bphen material results in efficient electron injection and transport, allowing for high luminous efficiency devices. The devices with neat $Alq_3$(Device1), 1:1 mixed $Alq_3$ : Bphen(Device2), and Bphen(Device3) have efficiency of 15.3cd/A, 16.9cd/A, 20.9cd/A, respectively, at $20\;mA/cm^2$. The efficiency characteristic of device with Bphen is best, but the device that is satisfied high efficiency and stability at once is observed in Device2.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.22 no.11
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• pp.980-986
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• 2009

In a triple-layered structure of ITO/N,N'-diph enyl-N,N'bis(3-methylphenyl)-1,1' - biphenyl-4,4'-diamine(TPD)/tris(8-hydroxyquinoline)aluminum($Alq_3$)/(2,9-Dimethyl-4,7-diphenyl-1,10-phenanthroline(BCP)/Al device, we have studied the electrical and optical characteristics of organic light-emitting diodes(OLEDs) depending on the deposition condition of BCP layer. Several different sizes of holes on boat and several different deposition rates were employed in evaporating the organic materials. And then, electrical properties of the organic light-emitting diodes were measured and the performance of the devices was analyzed. It was found that the hole-size of crucible boat and the evaporation rate affect on the surface roughness of BCP layer as well as the performance of the device. When the hole-size of crucible boat and the deposition rate of BCP are 1.2 mm and $1.0\;{\AA}/s$, respectively, average surface roughness of BCP layer is lower and the efficiency of the device is higher than the ones made with other conditions. From the analysis of current density-luminance-voltage characteristics of a triple layered device, we divided the conductive mechanism by four region according to applied voltage. So we have obtained a coefficient of ${\beta}_{ST}$ in schottky region is $3.85{\times}10^{-24}$, a coefficient of ${\beta}_{PF}$ in Poole-Frenkel region is $7.35{\times}10^{-24}$, and a potential barrier of ${\phi}_{FN}$ in Fower-Nordheim region is 0.39 eV.

• Korean Journal of Materials Research
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• v.7 no.10
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• pp.856-862
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• 1997

박막형 CdTe/CdS 태양전지의 배면전극(back contacts)물질로서 Cu도핑된 ZnTe 박막(ZnTe:Cu)을 전착법(electroplating)으로 제조하는 연구를 수행하였다. Sulfate계의 전해질 수용액에서 CdTe 기판과 투명전극으로 코팅된 유리(In$_{2}$O$_{3}$: Sn, ITO)기판 위에 ZnTe 박막을 코팅하는 방법으로써 potentiostat와 기판(cathode), Pt counter electrode, Ag/AgCI 표준전극으로 구성된 장치를 사용하여 pH=2.5-4, T=70-8$0^{\circ}C$, 0.02M $Zn^{2+}$ 1x$10^{-4}$M TeO$_{2}$, 0.2M $K_{2}$SO$_{4}$조건에서 -0.800 Vs~-0.975 V 범위의 전압(V$_{a}$ )에 걸쳐 실험하였다. ITO박막을 기판으로 사용하여 cyclic voltammogram을 작성한 결과 약 -0.50 V 에서 Te환원 peak이 나타났다. Auger electron spectroscopy (AES)로 조성분석한 결과 표면에서 Zn signal이 강하게 나왔고 시편의 두께에 따라 Zn의 signal감소하는 반면 Cd signal은 증가하는 것이 확인되었다. SEM 사진으로부터 ZnTe의 표면이 작은 입자 (0.2$\mu\textrm{m}$ 이하)로 구성되어 있으며 낮은 V$_{a}$ 에서는 입자가 작아지면서 조직이 치밀해짐이 관찰되었다. Optical transmission방법에 의하여 ITO기판위에 입혀진 박막의 밴드갭은 2.5 eV으로 측정되었다. 수용액중의 Cu$_{2+}$와 triethanolamine(TEA)은 산성용액에서 착물형성이 이루어지지 않았으며 1,10-phenanthroline과는 pH=2에서도 착물이 형성되었다.

• Korean Journal of Materials Research
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• v.18 no.4
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• pp.199-203
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• 2008

High-efficiency phosphorescent organic light emitting diodes using TCTA-TAZ as a double host and $Ir(ppy)_3$ as a dopant were fabricated and their electro-luminescence properties were evaluated. The fabricated devices have the multi-layered organic structure of 2-TNATA/NPB/(TCTA-TAZ) : $Ir(ppy)_3$/BCP/SFC137 between an anode of ITO and a cathode of LiF/AL. In the device structure, 2-TNATA[4,4',4"-tris(2-naphthylphenyl-phenylamino)-triphenylamine] and NPB[N,N'-bis(1-naphthyl)-N,N'-diphenyl-1,1'-biphenyl-4,4'-diamine] were used as a hole injection layer and a hole transport layer, respectively. BCP [2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline] was introduced as a hole blocking layer and an electron transport layer, respectively. TCTA [4,4',4"-tris(N-carbazolyl)-triphenylamine] and TAZ [3-phenyl-4-(1-naphthyl)-5-phenyl-1,2,4-triazole] were sequentially deposited, forming a double host doped with $Ir(ppy)_3$ in the [TCTA-TAZ] : $Ir(ppy)_3$ region. Among devices with different thickness combinations of TCTA ($50\;{\AA}-200\;{\AA}$) and TAZ ($100\;{\AA}-250\;{\AA}$) within the confines of the total host thickness of $300\;{\AA}$ and an $Ir(ppy)_3$-doping concentration of 7%, the best electroluminescence characteristics were obtained in a device with $100\;{\AA}$-think TCTA and $200\;{\AA}$-thick TAZ. The $Ir(ppy)_3$ concentration in the doping range of 4%-10% in devices with an emissive layer of [TCTA ($100\;{\AA}$)-TAZ ($200\;{\AA}$)] : $Ir(ppy)_3$ gave rise to little difference in the luminance and current efficiency.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.45 no.2
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• pp.161-173
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• 2019

In this study, the antioxidative and inhibitory activity of tyrosinase and collagenase for the solvent extract and silica column fractions of Artocarpus nitidus were evaluated. The activities were quantified using the 4 parameter logistic. LC/MS analysis showed that the major component of the fractions was polyphenol and the total polyphenol content of the extract was $48.1{\pm}2.6mg\;GAE/g$. The radical scavenging activities ($SC_{50}$) for 1,1-diphenyl-2-picrylhydrazyl of the extract, fraction-1 and fraction-2 were 16.7, 42.0 and $10.1{\mu}g/mL$, respectively. The value for fraction-2 was the closest to ascorbic acid ($1.5{\mu}g/mL$). The tyrosinase inhibitory activity of the extracts and the fractions showed $IC_{50}$ of 64.9, 0.9 and $1.2{\mu}g/mL$, respectively, and overall activity was higher than that of kojic acid ($7.4{\mu}g/mL$) and arbutin ($119.0{\mu}g/mL$). In the experiment by zebrafish embryo, the whitening activity of fraction-2 (27.5%) was higher than that of kojic acid (18.6%), and there was no adverse effect up to $500{\mu}g/mL$ of fraction-2. For the collagenase inhibitory activity, the samples showed $IC_{50}$ of 139.8, 20.6, and $16.8{\mu}g/mL$, respectively, which were competitive to 1, 10-Phenanthroline ($55.4{\mu}g/mL$). The extract and fraction-2 showed $IC_{50}$ of 61.8 and $67.1{\mu}g/mL$ for elastase. These results suggest that A. nitidus extract can be used as a cosmetic material useful for antioxidant, whitening, and prevention of skin aging without adverse effects.

• Bulletin of the Korean Chemical Society
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• v.33 no.5
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• pp.1675-1680
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• 2012

Three new cyanide-bridged $Cr^{III}Mn^{II}$ binuclear complexes, $[Mn(phen)_2Cl][Cr(bpmb)(CN)_2]{\cdot}H_2O$ ($\mathbf{1}$) (phen = 1,10-phenanthroline, $bpdmb^{2-}$ = 1,2-bis(pyridine-2-carboxamido)-4-methyl-benzenate), $[Mn(phen)_2Cl][Cr(bpmb)-(CN)_2]{\cdot}H_2O$ ($\mathbf{2}$) ($bpdmb^{2-}$ = 1,2-bis(pyridine-2-carboxamido)-4,5-dimethyl-benzenate), and $[Mn(phen)_2Cl]-[Cr(bpClb)(CN)_2]{\cdot}CH_3OH{\cdot}H_2O$ ($\mathbf{3}$) ($bpClb^{2-}$ = 1,2-bis(pyridine-2-carboxamido)-4-chloro-benzenate) were obtained based on $Mn(phen)_2Cl_2$ and a series of dicyanidechromate(III) building blocks. Single crystal X-ray diffraction analysis shows the structures of the three complexes are dimeric type with two different metal centers linked by a cyanide group from corresponding dicyanidechromate(III) building block. Magnetic investigations indicate the existence of relatively weak antiferromagnetic coupling between Cr(III) and Mn(II) ions with best-fit constants $J_{CrMn}=-2.78(5)cm^{-1}$ for $\mathbf{1}$, $J_{CrMn}=-3.02(2)cm^{-1}$ for $\mathbf{2}$ and $J_{CrMn}=-2.27(3)cm^{-1}$ for $\mathbf{3}$ based on the spin exchange Hamiltonian = $-2J_{CrMn}\hat{S}_{Cr}\hat{S}_{Mn}$. The magneto-structural correlation of cyanide-bridged $Cr^{III}Mn^{II}$ complexes has been discussed at last.

• Bulletin of the Korean Chemical Society
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• v.31 no.7
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• pp.1881-1886
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• 2010

Hydrothermal reaction of zinc(II) salts with 5-sulfoisophthalic acid monosodium salt ($NaO_3SC_6H_3$-1,3-(COOH)$_2$, $NaH_2$-SIP) and 1,10-phenanthroline (phen) led to two new compounds, [Zn(phen)$_3$$\cdot2H_2SIP\cdot4H_2O$ (1) and [Zn(phen)$_2(H_2O)_2]\cdot2H_2SIP\cdot2H_2O$ (2). They were characterized by element analysis, IR spectroscopy, thermalgravimetric analysis (TGA), X-ray powder diffraction (XRD), and single-crystal X-ray diffraction. Both compounds 1-2 represent the first example of Zn/phen/SIP system. The Zn (II) ion in 1 is six-coordinated by six nitrogen atoms from three phen molecules, and the $H_2SIP^-$ ligands engage in the formation of hydrogen bond. The Zn(II) ion in 2 is coordinated by four nitrogen atoms from two phen molecules and two oxygen atoms from two water molecules. Moreover, both 1 and 2 are assembled into 3D supramolecular architectures by hydrogen bonds (O-H$\ldots$O) and $\pi-\pi$ interactions. Solvent water molecules occupying voids of the compounds serve as receptors or donors of the extensive O-H$\ldots$O hydrogen bonds.

• Journal of the Korean Applied Science and Technology
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• v.26 no.1
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• pp.24-28
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• 2009

본 논문에서는 청색 인광 발광 물질인 bis(3,5-Difluoro-2-(2-pyridyl)phenyl-(2-carboxypyridyl) iridium (III) (Flrpic)과 녹색 인광 발광 물질인 fac-tris(2-phenypyridine) irdium(III) ($Ir(ppy)_3$)와 적색 인광 발광 물질인 his(5-benzoyl-2-phenylpyridinato-C,N)iridium(III) (acetylacetonate) ($(Bzppy)_{2}Ir(acac)$)를 각각 적층하여 백색 유기 발광 다이오드를 제작하였고, 각각의 발광층 사이에 혼합된 스페이서인 4,4'-N,N'-dicarbazole-biphenyl (CBP):4,7-diphenyl-1,10-phenanthroline (BPhen)을 적층하여 그 때의 영향에 대하여 연구하였다. 최적화된 구조에서의 전력 효율은 $0.014\;mA/cm^2$에서의 19.7 lm/w를 나타내었으며, $0.127\;mA/cm^2$에서의 11.5%의 외부 양자 효율을 나타내었고, 8 V에서 Commission Internationale do I'Eclairage ($CIE_{x,y}$) coordinates (x=0.36, y=0.44)의 색좌표를 나타내었다.

• BMB Reports
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• v.38 no.1
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• pp.104-110
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• 2005

We extended the measurable time scale of DNA dynamics to microsecond using $[Ru(phen)_2(dppz)]^{2+}$ (phen = 1,10-phenanthroline, dppz = dipyrido[3,2-a:2',3'-c]phenazine) (RuPD), which displays a mean lifetime near 500 ns. To evaluate the usefulness of this luminophore (RuPD) for probing nucleic acid dynamics, its intensity and anisotropy decays when intercalated into supercoiled and linear pBluescript (pBS) II SK(+) phagemids were examined using frequency-domain fluorometry with a blue light-emitting diode (LED) as the modulated light source. The mean lifetime for the supercoiled phagemids (< $\tau$ > = 489.7 ns) was somewhat shorter than that for the linear phagemids (< $\tau$ > = 506.4 ns), suggesting a more efficient shielding from water by the linear phagemids. The anisotropy decay data also showed somewhat shorter slow rotational correlation times for supercoiled phagemids (997.2 ns) than for the linear phagemids (1175.6 ns). The slow and fast rotational correlation times appear to be consistent with the bending and torsional motions of the phagemids, respectively. These results indicate that RuPD can have applications in studies of both bending and torsional dynamics of nucleic acids.