• Title/Summary/Keyword: $\b{ZnS}$

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A Study on the ZnO Piezoelectric Thin Film SAW Filter for High Frequency (ZnO 압전 박막을 이용한 고주파 SAW 필터 연구)

  • 박용욱;신현용
    • Journal of the Korean Ceramic Society
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    • v.40 no.6
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    • pp.547-552
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    • 2003
  • ZnO thin films on glass substrate were deposited by RF magnetron reactive sputtering at 100 W, 1.33 Pa, Ar/O2=50 : 50, 200$^{\circ}C$, and a target/substrate distance of 4 cm. Crystallinities, surface morphologies, chemical compositions, and electrical properties of the films were investigated by XRD, SEM, AFM, RBS, and electrometer. All films showed a strong preferred c-axis orientation and the chemical stoichiometry. The propagation velocity of ZnO/IDT/glass of single electrode and double electrode types SAW filter was about 2,589 m/sec, 2,533 m/sec and insertion loss was a minimum value of about -11 dB and -21 dB, respectively.

The Study on Chemical Durable Zinc-phosphate Glasses with $B_2$$O_3$Addition ($B_2$$O_3$첨가에 따른 Zinc Phosphate Glasses의 화학적 안정화)

  • 류봉기;이병철;이성욱;황차원;이종성
    • Journal of the Korean Ceramic Society
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    • v.38 no.6
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    • pp.593-595
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    • 2001
  • Zinc-phosphate glasses에 B$_2$O$_3$를 도입하여 borate, phosphate, boro-phosphate networks가 혼재되어 있는 highly cross-linked structures를 형성시켜 Phosphate glasses의 화학적 안정화를 검토하였다. Raman 측정 결과 B$_2$O$_3$와 P$_2$O$_{5}$는 잘 혼화된 polynary networks를 이루고 있으며, 이렇게 하여 증진된 구조적 cross-linking에 의하여 xB$_2$O$_3$.(1-x)Zn$_2$P$_2$O$_{7}$ glasses의 T$_{g}$, T$_{d}$는 증가하였고 동시에 CTE는 감소하는 결과를 가져왔다.

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Binding energy study from photocurrent signal inphotoconductive a $ZnIn_2S_4$ thin films

  • Hong, Kwang-Joon
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2010.06a
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    • pp.380-380
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    • 2010
  • The chalcopyrite $ZnIn_2S_4$ epilayers were grown on the GaAs substrate by using a hot-wall epitaxy (HWE) method. The crystal field and the spin-orbit splitting energies for the valence band of the $ZnIn_2S_4$ have been estimated to be 0.1541 eV and 0.0129 eV, respectively, by means of the photocurrent spectra and the Hopfield quasicubic model. These results indicate that the splitting of the ${\Delta}so$ definitely exists in the $\Gamma_5$ states of the valence band of the $ZnIn_2S_4$/GaAs epilayer. The three photocurrent peaks observed at 10 K are ascribed to the $A_{1^-}$, $B_{1^-}$, and $C_1$-exciton peaks for n = 1. Also, we obtained the $A_{\infty^-}$ and B-exciton peaks from the PC spectrum at 293 K.

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The Comparison of X-ray Response Characteristics of Vacuum Evaporated $Cd_{1-x}Zn_{x}Te$ Detector (진공증착된 $Cd_{1-x}Zn_{x}Te$ 검출기의 X선 반응 특성 비교)

  • Kang, S.S.;Choi, J.Y.;Lee, D.G.;Cha, B.Y.;Kim, J.H.;Nam, S.H.
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2002.05b
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    • pp.39-42
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    • 2002
  • There is a renewed interest in the application of photoconductors especially Cd(Zn)Te to x-ray imaging. In this paper, We investigate effects on x-ray detection characteristic of Zn dopped CdTe detector. Cd(Zn)Te film was fabricated by vacuum thermal evaporation method and then investigate physical analysis using EPMA and XRD. We investigated the leakage current and X-ray photosensitivity as applied voltage about fabricated Cd(Zn)Te film. Experimental results showed that the increase of Zn dopped concentration in $Cd_{1-x}Zn_{x}Te$ detector reduced a leakage current and improved a signal to noise ratio significantly.

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Magenetic Properties of Co, Ni and Ca Substituted Mn-Zn Ferrite (Co, Ni 및 Ca를 첨가한 Mn-Zn 페라이트의 자기적 성질)

  • 하태욱;이정식
    • Journal of the Korean Magnetics Society
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    • v.5 no.1
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    • pp.15-20
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    • 1995
  • We have prepared 20 kinds of Mn-Zn ferrites as content of CaO(0.1 mol%), NiO(0.0~0.60 mol%) and CoO(0.0~0.8 mol%) adding by the coprecipitation method and studied the magnetic properties as content of CaO, NiO and CoO adding. Initial permeability decrease as the content of NiO and CoO adding increases, while Curie tem~ perature increase as the content of NiO and CoO adding increases. $(H_{c})$, $(B_{s})$ and $(W_{h})$ increase as content of NiO adding increases.

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The Magnetic Field Dependence Properties of Quasi Two Dimensional Electron-piezoelectric Potential Interacting System in GaN and ZnO

  • Lee, S.H.;Sug, J.Y.;Lee, J.H.;Lee, J.T.
    • Journal of Magnetics
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    • v.16 no.4
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    • pp.408-412
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    • 2011
  • We investigated theoretically the magnetic field dependence of the quantum optical transition of qusi 2-Dimensional Landau splitting system, in GaN and ZnO. We apply the Quantum Transport theory (QTR) to the system in the confinement of electrons by square well confinement potential. We use the projected Liouville equation method with Equilibrium Average Projection Scheme (EAPS). Through the analysis of this work, we found the increasing properties of the optical Quantum Transition Line Shapes(QTLSs) which show the absorption power and the Quantum Transition Line Widths(QTLWs) with the magnetic-field in GaN and ZnO. We also found that QTLW, ${\gamma}(B)_{total}$ of GaN < ${\gamma}(B)_{total}$ of ZnO in the magnetic field region B < 25 Tesla.

HNO3 Etching Properties of BaO-B2O3-ZnO-P2O5 System of Barrier Ribs in PDP (플라스마 디스플레이 패널의 격벽용 BaO-B2O3-ZnO-P2O5계의 HNO3를 이용한 에칭 특성)

  • Jeon, J.S.;Kim, J.M.;Kim, N.S.;Kim, H.S.
    • Korean Journal of Materials Research
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    • v.16 no.4
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    • pp.235-240
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    • 2006
  • We investigated the effect of ZnO filler on the microstructure of $BaO-B_2O_3-ZnO-P_2O_5$ glass system to find an etching mechanism of barrier ribs. The sintering behavior of composites heated in the temperature range $560-600^{\circ}C$ was studied by volumetric shrinkage rate and microstructure. The etching test was carried out in $HNO_3$ solution at $50^{\circ}C$ for 10 min. The volumetric shrinkage of sintered sample decreased with the increased firing temperature because of the formation of two crystals. Glass and ZnO filler react forming the $BaZn_2(PO_4)_2$ crystal phases during the sintering process. Etching phenomenon of sintered samples by $HNO_3$ showed that the $BaZn_2(PO_4)_2$ crystal phase was strongly leached compared to glass matrix, crystal phases and fillers. Therefore, the control of interface by condition of sintering is so important to achieve etching effect in barrier ribs.

Synthesis and enhancements of exciton-phonon interactions for ZnO nanopencils by thermal evaporation (ZnO nanopencils의 합성과 향상된 exciton-phonon interactions)

  • Ahn, C.H.;Woo, C.H.;Bae, Y.S.;Choi, M.K.;Kim, Y.Y.;Kim, D.C.;Kong, B.H.;Cho, H.K.
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2009.06a
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    • pp.45-45
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    • 2009
  • 우리는 ZnO Template를 사용한 열기상법을 이용하여 수직 배양한 ZnO nanorods와 ZnO Nanopencils를 성장하였고, Dependency temperature Photoluminescence(PL)의 분석을 통하여 광학적 특성에 대해 분석을 하였다. ZnO 나노구조는 100K 이하의 온도에서 donor-bound exciton가 dominant하고, 100K 이상의 온도에서는 free exciton과 그들의 phonon-replica emission이 dominant한 것을 알 수 있었다. 하지만, ZnO nanorods와 nanopencils은 다른 exciton-phonon coupling의 strength에 의한 surface defects에 의해 excitonic emissions의 다른 거동을 보이는 것을 알았다. 이것으로 인해 상온 PL에서 ZnO nanopencil은 nanorods에 비해 52meV의 red shift를 보였다.

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Stimulative Effects of Hominis Placental Pharmacopuncture Solution Combined with Zinc-oxide Nanoparticles on RAW 264.7 Cells - ZnO HPPS more easily stimulates RAW 264.7 cells -

  • Hong, Tae-Keun;Kim, Jee-Hye;Woo, Ju-Youn;Ha, Ki-Tae;Joo, Myung-Soo;Hahn, Yoon-Bong;Jeong, Han-Sol
    • Journal of Pharmacopuncture
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    • v.15 no.3
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    • pp.13-18
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    • 2012
  • Objectives: The purpose of this study is to examine whether Hominis Placental pharmacopuncture solution (HPPS) combined with zinc-oxide nanoparticles (ZnO NP) activates RAW 264.7 cells. Methods: We soaked ZnO nanoparticles in the Hominis Placenta pharmacopuncture solution, thereby making a combined form (ZnO NP HPPS). The effect of ZnO NP HPPS on the intracellular reactive oxygen species (ROS) production was measured by 2', 7'-dichlorofluorescin diacetate (DCFH-DA) assay. The effect of ZnO NP HPPS on NF-${\kappa}B$ was measured by using a luciferase assay. The effect of ZnO NP HPPS on the cytokine expression was assessed by semi-quantitative reverse transcriptase polymerase chain reaction (RT-PCR). The cellular uptake of ZnO NP HPPS was measured by using a flow cytometric analysis, and cellular structural alterations were analyzed by using transmission electron microscopy (TEM). Results: Neither the HPPS nor the ZnO NPs induced intracellular ROS production in RAW 264.7 cells. Neither of the materials activated NF-${\kappa}B$ or it's dependent genes, such as TNF-${\alpha}$, IL-1, and MCP-1. However, ZnO NP HPPS, the combined form of ZnO NPs and HPPS, did induce the intracellular ROS production, as well as prominently activating NF-${\kappa}B$ and it's dependent genes. Also, compared to ZnO NPs, it effectively increa-sed the uptake by RAW 264.7 cells. In addition, cellular structural alterations were observed in groups treated with ZnO NP HPPS. Conclusions: Neither ZnO NP nor HPPS activated RAW 264.7 cells, which is likely due to a low cellular uptake. The ZnO NP HPPS, however, significantly activated NF-${\kappa}B$ and up-regulated its dependent genes such as TNF-${\alpha}$, IL-1, and MCP-1. ZnO NP HPPS was also more easily taken into the RAW 264.7 cells than either ZnO NP or HPPS.

The study of diode characteristics on the doping concentration of ZnO films using the Si Substrate (Si 기판위에 형성된 ZnO 박막의 도핑 농도에 따른 다이오드 특성 연구)

  • Lee, J.H.;Jang, B.L.;Lee, J.H.;Kim, J.J.;Kim, H.S.;Jang, N.W.;Cho, H.K.;Kong, B.H.;Lee, H.S.
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2008.06a
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    • pp.216-217
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    • 2008
  • Zinc-oxide films were deposited by pulsed laser deposition (PLD) technique using doped ZnO target (mixed $In_2O_3$ 0.1, 0.3, 0.6 at. % - atomic percentage) on the p-type Si(111) substrate. A little Indium has added at the n-ZnO films for the electron concentration control and enhanced the electrical properties. Also, post thermal annealed ZnO films are shown an enhanced structural and controled electron concentration by the annealing condition for the hetero junction diode of a better emitting characteristics. The electrical and the diode characteristics of the ZnO films were investigated by using Hall effect measurement and current-voltage measurement.

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