• Bulletin of the Korean Chemical Society
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• 제30권12호
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• pp.3109-3112
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• 2009

• 대한화학회지
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• 제15권2호
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• pp.49-54
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• 1971

It is shown that the impurities of Cu(II), Pb(II), Zn(II) and Ag(I) in Bismuth metal and the components of Pb(II), Zn(II) and Sn(IV) in Bismuth alloy are separated into their components from each other by elutions through $3.14cm^2{\times}10cm$ cation exchange resin, $Dowex\;50w\;{\times}\;8$ (100~200 mesh), column with the mixed solutions of HAc and NaAc as the eluents. The elution curve of Fe(III) has a long tailing and is not separated quantitatively from Bi(III). The eluents used for this separation are as follows; 1M HAc + 0.1M NaAc (pH 3.36) for Fe(III) and Bi (III). 0.3M HAc + 0.3M NaAc (pH 4.70) for Cu(II), Pb(II) and Zn(II). 0.5M HAc + 0.5M NaAc (pH4.70) for Ag(I) and Sn(IV). The analysis of cations eluted are carried out by spectrophotometry and EDTA titrimetry. Their recoveries are more than 99%.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2013년도 제45회 하계 정기학술대회 초록집
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• pp.213-213
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• 2013

화합물 반도체 양자점(Quantum dots; QDs)은 높은 효율의 광전자 소자에 적용할 수 있기 때문에 이분야에 대한 연구가 활발히 진행되고 있지만 주로 III-V 족 화합물 반도체에 대한 연구가 주를 이룬 반면 II-VI 족 화합물 반도체에 대한 연구는 아직 미흡하다. 하지만 II-VI 족 화합물 반도체는 III-V 족 화합물 반도체와 비교했을 때 더 큰 엑시톤 결합에너지(exciton binding energy)를 가지는 우수한 특성을 보이고 있으며 이러한 성질을 가지는 II-VI 족 화합물 반도체 중에서도 넓은 에너지 갭을 가지는 $Cd_xZn_{1-x}Te$ 양자점은 녹색 영역대의 광전자 소자로서 활용되고 있다. 현재 대부분의 $Cd_xZn_{1-x}Te$ 양자점 구조는 기판과 완충층 (buffer layer) 사이의 작은 격자 부정합(lattice mismatch) 때문에 GaAs 기판을 이룬 반면 Si기판을 이용한 연구는 미흡하다. 하지만 Si 기판은 GaAs 기판에 비해 값이 싸고, 여러 분야에 응용이 가능하며 대량생산이 가능하다는 이점을 가지고 있어 초고속, 초고효율 반도체 광전소자의 제작을 가능케 할 것으로 기대된다. 또한 양자점의 고효율 광전소자에 응용을 위해서는 Si 기판 위에 양자점의 크기를 효율적으로 조절하는 연구 뿐 아니라 양자점의 크기에 따른 운반자 동역학에 대한 연구도 중요하다. 본 연구에선 분자선 에피 성장법(Molecular Beam Epitaxy; MBE)을 이용하여 Si 기판위에 성장한 $Cd_xZn_{1-x}Te/ZnTe$ 양자점의 크기에 따른 광학적 특성을 연구하였다. 저온 광 루미네센스 (PhotoLuminescence; PL) 측정 결과 양자점의 크기가 증가함에 따라 더 낮은 에너지영역으로 피크가 이동하는 것을 확인하였다. 그리고 시분해 광루미네센스 측정 결과 $Cd_xZn_{1-x}Te/ZnTe$ 양자점의 크기가 증가함에 따라 소멸 시간이 긴 값을 갖는 것을 관찰 하였는데, 이는 양자점의 크기가 증가함에 따라 엑시톤 진동 세기가 감소하였기 때문이다. 또한 온도 의존 광루미네센스 측정 결과 양자점의 크기가 증가함에 따라 열적 활성화 에너지가 증가하는 것을 관찰 하였는데, 이는 양자점의 운반자 구속효과가 증가하였기 때문이다. 이와 같은 결과 Si 기판 위에 성장한 $Cd_xZn_{1-x}Te/ZnTe$ 양자점의 크기에 따른 광학적 특성에 대해 이해 할 수 있었다.

• 한국환경과학회:학술대회논문집
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• 한국환경과학회 2006년도 추계 학술발표회 발표논문집
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• pp.340-344
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• 2006

• 한국결정학회지
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• 제16권2호
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• pp.107-127
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• 2005

Five Cu(II) compounds were obtained from different copper salts with btp ligands, and their structures were determined by X-ray crystallography. The structure of coordination polymer 2 contains btp-bridged tetranuclear Cu(II) units weakly connected by nitrate ions, and the structure of a discrete Cu(II) molecule 1 contains acetates and btp ligands. With perchlorate anions, two btp ligands bridge Cu(II) ions to form a double zigzag chain 3, while a single zigzag chain 4 is created with sulfate anions. The reaction of $Cu(NO_{3})_{2}$ containing $NH_{4}PF_{6}$ with btp ligands also produced a polymeric compound 5 containing $Cu(H_{2}O)_{2}^{2+}$ and $Cu(NO_{3})_{2}$ units alternatively bridged by btp ligands with H-bonds between copper bonded water and nitrate oxygen atoms. Five Zn(II) compounds were obtained from different zinc salts with btp ligands, and the structures of polymeric compounds (6, 7 and 8) and monomeric compounds (9 and 10) were determined by X-ray crystallography. With nitrate, chloride and bromide anions, btp ligands bridge Zn(II) ions to form polymeric compounds (6, 7 and 8), but btp ligands coordinate to a Zn(II) ion to form monomeric complexes (9 and 10) with $PF_{6}^{-}$ and perchlorate anions. Four silver salts and btp ligands produced two kinds of structures, dinuclear 20-membered rings and one-dimensional zigzag chain depending on different anions. For $ClO_{4}^{-}$ and OTf anions, weak interactions between Ag(I) and anions make dinuclear 20-membered rings construct polymeric compounds (11 and 13). For $PF_{6}^{-}$ anion, there are also weak interactions between Ag(I) and $F(PF_{6}^{-})(12)$, but they do not construct a polymeric compound. For $O_{2}CCF_{3}^{-}$ anion, btp ligands bridge Ag(I) atoms to make one-dimensional zigzag chain (14), and there are also interactions between Ag(I) and anions.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2002년도 하계학술대회 논문집 Vol.3 No.2
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• pp.752-755
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• 2002

Since Metallo-Porphyrin (MP) is very interesting compound due to its unique electronic and redox properties and it is also chemically and thermally stable, MP has been studied for potential memory and switching devices. In this study, thin films of 5,10,15,20 - Tetrakis - Octadecyloxymethylphenyl - Porphyrin - Zn(II) (Zn-TPP) were prepared by the Langmuir-Blodgett (LB) method and characterized by using UV/vis absorption spectroscopy and cyclic voltammetry. It was found that the proper transfer surface pressure for film deposition was 25 mN/m and the limiting area per molecule was $135{\AA}^2$/molecule. The current-voltage (I-V) characteristics of these films were investigated.

• 전기학회논문지
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• 제63권1호
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• pp.76-79
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• 2014

We report Zinc oxide (ZnO) nanorods synthesis and electrochemical luminescence (ECL) cell fabrication. The ECL cell was fabricated using the electrode of ZnO nanorods and Ru(II) complex ($Ru(bpy)_3{^{2+}}$) as a luminescence materials. The fabricated ECL cell is composed of F-doped $SnO_2$ (FTO) glass/ Ru(II)/ZnO nanorods/FTO glass. The highest intensity of the emitting light was obtained at the wavelength of ~620 nm which corresponds to dark-orange color. At a bias voltage of 3V, the measured ECL efficiencies were 5 $cd/m^2$ for cell without ZnO nanorod, 145 $cd/m^2$ for ZnO nanorods-$5{\mu}m$, 208 $cd/m^2$ for ZnO nanorods-$8{\mu}m$ and 275 $cd/m^2$ for ZnO nanorods-$10{\mu}m$, respectively. At a bias voltage of 3.5V, the use of ZnO nanorods increases ECL intensities by about 3 times compared to the typical ECL cell without the use of ZnO nanorods.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2002년도 추계학술발표회
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• pp.302-305
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• 2002

Scoria is a bomb-sized, generally vesicular pyroclast that is red or black in color and light in weight. In this study, scoria from Cheju was examined for the use as a sorbent. It is composed of plagioclase, olivine, hornblende, pyroxene, and glass, with an average composition of 49.84% SiO$_2$, 14.07% A1$_2$O$_3$, End 9.14% Fe$_2$O$_3$. Studies on kinetic isotherm sorption of Zn(II) onto scoria under various parameters such as initial zinc concentration, particle size, and adsorbent/adsorbate ratio were carried out using an agitated batch. The results suggest that the smaller scoria size and the larger adsorbent/adsorbate ratio produce the higher degree of Zn(II) removal. More effective removal also appears at lower initial Zn concentration. The sorption behavior of Zn(II) onto scoria seems to be mainly controlled by cation exchange. Studies on equilibrium isotherm sorption of other heavy metals (Pb, Cu, Cd) onto scoria were also conducted and compared with those onto powdered activated carbon (PAC) and non-organic matter scoria (NOS), The results suggest that the Cheju scoria has the slightly higher sorption capability than PAC and NOS, and the order of the effective sorption onto scoria and PAC is Pb > Cu > Zn > Cd. The monometal sorption onto scoria is more stronger than the competitive sorption.

• 한국진공학회지
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• 제6권1호
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• pp.50-60
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• 1997

순수한 $ZnAl_2S_4,;ZnAl_2Se_4,;CdAl_2S_4,;and;CdAl_2Se_4$ 및 cobalt와 erbium을 불순물로 첨가 한 이들 단결정을 화학수송법으로 성장시켰다. 성장된 단결정의 결정구조, 격자상수, 광학적 energy gap, photoluminescence 특성 등을 측정하여 광학적 전이 기구를 규명하였다.

• Bulletin of the Korean Chemical Society
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• 제32권8호
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• pp.2617-2622
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• 2011

Two new Zn(II) complexes, $[Zn_2(dpa)_2(phen)_2(H_2O)_2]{\cdot}H_2O$ (1) (dpa = dephenate, phen = 1,10-phenanthroline) and [$Zn_2(dpa)_2(bpy)_2(H_2O)_2$] (2) (bpy = 2,2'-bipyridine) have been synthesized and characterized by elemental analysis, infrared spectroscopy, thermogravimetric analysis, and single crystal X-ray diffraction. The X-ray analysis reveals that the structures of 1 and 2 are dinuclear zinc(II) complexes bridged by dpa dianions, respectively. The zinc ions in 1 exhibit a distorted square pyramidal environments, while the zinc ions in 2 exhibit a trigonal bipyramid geometry. In each complex, the dpa ligand is coordinated to zinc ions as a bis-monodentate.