• Korean Journal of Materials Research
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• v.21 no.1
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• pp.46-49
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• 2011

Bi co-doped ZnS:Mn,Bi yellow phosphors for white light emitting diodes were prepared by the conventional solidstate reaction method. The optical and structural properties of ZnS:Mn,Bi phosphors were investigated by x-ray diffraction, scanning electro microscopy and photoluminescence. ZnS:Mn,Bi phosphors showed XRD patterns of hexagonal structure. The photoluminescence of ZnS:Mn,Bi phosphors showed spectra extending from 480 to 700 nm, peaking at 580 nm. The photoluminescence of 580 nm in the ZnS:Mn,Bi phosphors was associated with the 4T1 ${\rightarrow}$ 6A1 transition of the Mn2+ ions. The highest photoluminescent intensity of the phosphors under 405 nm and 450 nm excitation was obtained at Bi concentration of 7mol%. The optimum mixing conditions with epoxy and yellow phosphor for white light emitting diodes were observed in a ratio of epoxy:yellow phosphor of 1:3.5. The CIE chromaticity of the white LED at the 1:3.5 ratio was X = 0.3454 and Y = 0.2449.

• JSTS:Journal of Semiconductor Technology and Science
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• v.14 no.1
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• pp.92-95
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• 2014

In this work we have synthesized ZnS:Mn nanocrystals (NCs) using a simple one step thermochemical method. $Zn(NO_3)_2$ and $Na_2S_2O_3$ were used as the precursors and $Mn(NO_3)_2$ was the source of impurity. Thioglycolic acid (TGA) was used as the capping agent and the catalyst of the reaction. The structure and optical property of the NCs were characterized by means of X- ray diffraction (XRD), HRTEM, UV-visible optical spectroscopy and photoluminescence (PL). X-ray diffraction (XRD) and transmission electron microscopy (TEM) analyses demonstrated cubic phase ZnS:Mn NCs with an average size around 3 nm. Synthesized NCs exhibited band gap of about 4 eV. Photoluminescence spectra showed a yellow-orange emission with a peak located at 585 nm, demonstrating the Mn incorporation inside the ZnS particles.

• Corrosion Science and Technology
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• v.16 no.4
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• pp.183-186
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• 2017

Galvanic corrosion tests of Zn/steel couples were conducted in 1 M NaCl and $1M\;MgCl_2$ solutions to investigate the impact of magnesium ion on corrosion behavior of the couples. Two types of Zn/steel couples were used for measurements of open circuit potential (OCP) and galvanic current. From the results of OCP transient of Zn/steel couples, the corrosion potential in $1M\;MgCl_2$ was a more positive value than that in 1 M NaCl during the sacrificial dissolution of Zn. However, earlier increase of OCP of the couples in $1M\;MgCl_2$ solution indicates that the sacrificial dissolution rate of Zn in $1M\;MgCl_2$ was enhanced more than that in 1 M NaCl, agreeing with the results on transients of galvanic current. This result is due to that cathodic reaction on the steel surface of the Zn/steel couple was enhanced in $1M\;MgCl_2$ by the occurrence of hydrogen evolution reaction.

• Journal of Advanced Marine Engineering and Technology
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• v.9 no.3
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• pp.240-249
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• 1985

This paper presents the results of the galvanic anode's characteristicsin the Al-Zn-In-Mg and Al-Zn-In-Mg system anodes used aluminium ingot of low purity, 99.5% grade. The results of thses performance tests are as follows: 1) Zn, In and Mg are an available elements to improve the performance of Aluminium alloy anodes. 2) When the range of zinc content in the Al-Zn-In-Mg system anode is 2-5% the more zinc content, the more improve the anode performance. 3) Al-Zn-In-Mg system anode requires a long term over 50 days for the performance test. 4) The composition of Al-Zn-In-Mg system anode which shows the most excellent performance is Al-(2-3%) Zn-(0.02%) In-(1.0%) Mg. 5) When the Al-Zn-In-Mg system anode is annealed for an hour in 500 to 550 .deg. C, the anode performance is improved. 6) The lower average potential and the better corrosion pattern in the Al-Zn-Mg, Al-Zn-In and Al-Zn-In-Mg system anodes, the more current efficiency is improved.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1989.06a
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• pp.26-28
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• 1989

In this paper, The preparation and characteristics of polyaniline/Zn battery by (NH$_4$)$_2$S$_2$O$\sub$8/ and used as cathod active material to investigate the characteristics of polyaniline/Zn battery. Characteristics of polyaniline/Zn battery was affected of amounts of electrolytes and additives such as graphite and carbon black.

• Journal of the Korean Ceramic Society
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• v.30 no.6
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• pp.499-509
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• 1993

Structures of hematite(${\alpha}$-Fe2O3), Ba-ferrite(BaFe12O19) and Zn2Y(Ba2Zn2Fe12O22) were studied by powder X-ray diffraction(XRD) method. Powder XRD patterns of the ferrites were analyzed with the Rietveld method, and the final refined R-factors were RWP<0.01 and RI<0.03. The lattice parameters refined with hexagonal crystal system were a=5.0342${\AA}$, c=13.746${\AA}$ for hematite, a=5.8928${\AA}$, c=23.201${\AA}$ for Ba-ferrite, and a=5.8763${\AA}$, c=43.567${\AA}$ for Zn2Y. In the hematite, the oxygen parameter is 0.3072 and the Fe-O distances in FeO6octahedron are 1.941${\AA}$ and 2.118${\AA}$, close to the single crystal data of Blake et al.. In the Ba-ferrite, the Fe atom in oxygen trigonal bipyramid is displaced 0.155${\AA}$ away from the BaO3 mirror plane into 4e position. In the Zn2Y, 75% of Zn is located at the oxygen terahedral site in S-block.

• Journal of Advanced Marine Engineering and Technology
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• v.27 no.1
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• pp.33-41
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• 2003

The optical properties of $ZnS_ySe_{1-\chi-y}:Te_{\chi}(\chi<0.08,y~0.11)$ alloys grown by molecular beam epitaxy (MBE) have been investigated by photoluminescence (PL) and PL-excitation (PLE) spectroscopy. Good optical properties and high crystal quality were established with lattice match condition to GaAs substrate. At room temperature, emission in the visible spectrum region from blue to green was obtained by varying the Te content of the ZnSSe:Te alloy. The efficient blue and green emission were assigned to $Te_1 and Te_n(n\geq2)$cluster bound excitons, respectively. Bright green (535 nm) and blue (462 nm) light emitting diodes (LEDs) have been developed using ZnSSe:Te system as an active layer. The turn-on voltage of 2.1 V in current-voltage characteristics is very small compared to that of commercial InGaN-based LEDs (>3.4 V), indicating the formation of a good ohmic contact due to the optimized p-ZnSe/p-ZnTe multi-quantum well (MQW) superlattice electrode layers.

• Current Applied Physics
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• v.18 no.12
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• pp.1571-1576
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• 2018

Recent study shows that the main reason for limiting CZTS device performance lies in the low open circuit voltage, and crucial factor that could affect the $V_{oc}$ is secondary phases like ZnS existing in absorber layer and its interfaces. In this work, the $Cu_2ZnSnS_4$ thin film solar cells were prepared by sputtering CuSn and CuZn alloy targets. Through tuning the Zn/Sn ratios of the CZTS thin films, the crystal structure, morphology, chemical composition and phase purity of CZTS thin films were characterized by X-Ray Diffraction (XRD), scanning electron microscopy (SEM) equipped with an energy dispersive spectrometer (EDS) and Raman spectroscopy. The statistics data show that the CZTS solar cell with a ratio of Zn/Sn = 1.2 have the best power convention efficiency of 5.07%. After HCl etching process, the CZTS thin film solar cell with the highest efficiency 5.41% was obtained, which demonstrated that CZTS film solar cells with high efficiency could be developed by sputtering CuSn and CuZn alloy targets.

• Journal of the Korean Institute of Gas
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• v.9 no.4 s.29
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• pp.26-29
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• 2005

In this paper, the solvent sensing properties of the metallophthalocyanine macrocyclic compounds(ZnPc) have been deposited as thin films by the spin-coated method and evaporated methods onto alumina substrates and quartz substrates. And then the spin-coated materials of Zinc phthalocyanine solutions blended with $N,N'-diphenyl-N,N'-bis(1-naphthyl)-1,\;1-biphenyl-4,4'-diamine\;and/or\; Poly[2-methoxy-5-(2'-ethylhexyloxy)-1,4-phenylene-vinylene]$ solutions. The influences of the blended metallophthalocyanine macrocyclic compounds on the resistance have been measured and analysed in five different vapour organic compounds.

• Korean Journal of Materials Research
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• v.4 no.8
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• pp.847-854
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• 1994

An amorphous single phase and coexistent amorphous and hcp-Mg phases in Mg-Zn-Ce system were found to form in the composition ranges of 20 to 40% Zn, 0 to 10% Ce and 5 to 20% Zn, 0 to 5% Ce, respectively. A $Mg_{85}Zn_{12}Ce_{3}$ amorphous alloy containing nanoscale hcp-Mg particles was found to form either by melt spinning or by heat treatment of melt -spun ribbon. The particle size of the hcp-Mg phase can be controlled in the range of 4 to 20 nm. The mixed phase alloy prepared thus has a good bending ductility and exhibits high ultimate tensile strength($\sigma_{B}$) ranging from 670 to 930 MPa and fracture elongation($\varepsilon_{f}$) of 5.2 to 2.0%. The highest specific strength($\sigma_{B}$/density =$\sigma_{s}$)$3.6 \times 10^5N \cdot m/kg$. It should be noted that the highest values of flB, US and ？1 are considerably higher than those (690MPa,$2.5 \times 10^5N \cdot m/kg$and 2.5%) for amorphous Mg-Zn-Ce alloys. The increase of the mechanical strengths by the formation of the mixed phase structure is presumably due to a dispersion hardening of the hcp supersaturated solution which has the hardness higher than that of the amorphous phase with the same composition.