• Title/Summary/Keyword: ZnO/Cu/ZnO

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Change of Optical Properties in Zinc Oxide-Based Glasses including Metal Oxides for Transparent Dielectric

  • Seo, Byung-Hwa;Kim, Hyung-Sun;Suh, Dong-Hack
    • Korean Journal of Materials Research
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    • v.19 no.10
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    • pp.533-537
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    • 2009
  • This paper presents a new method for the improvement of color temperature without the change of the driving scheme using transparent dielectric layers with various metal oxides (CeO$_2$, Co$_3$O$_4$, CuO, Fe$_2$O$_3$, MnO$_2$, NiO) in plasma display panels (PDP). In this study, we fabricated ZnO-B$_2$O$_3$-SiO$_2$-Al$_2$O$_3$ glasse with various metal oxides and examined the optical properties of these glasses. As the metal oxides were added to the glasses, the visible transmittances of the dielectric layers decreased and the transmittances in special wavelength regions were reduced at different rates. The change of the transmittance in each wavelength range induced the variation of the visible emission spectra and the change of the color temperature in the PDP. The addition of Co$_3$O$_4$ and CuO slightly decreased the intensity of the blue light, but the intensities of the green and the red light were significantly decreased. Therefore, the color temperature can be improved from 6087K to 7378K and 7057K, respectively.

Heavy Metal Accumulation in Oxyloma hirasei from the Upo Wetland

  • Kim, Heung-Tae;Kim, Jae-Geun
    • Journal of Ecology and Environment
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    • v.30 no.1
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    • pp.81-86
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    • 2007
  • Human activities have enhanced the influx of heavy metals to aquatic ecosystem and hanged the abiotic environment such as the sediments supporting benthic organisms. The levels of heavy metals (Cd, Cr, Cu, Ni, Pb and Zn) in the benthic gastropod Oxyloma hirasei and the sediments around their habitat were investigated to examine heavy metal levels and the potential of the gastropod as a bioindicator. We detected different levels of heavy metals in the sediments of two wetland areas, Upo and Mokpo, in the relatively well-conserved Upo wetland, Ramsar Convention Area. Oxyloma hirasei had higher concentrations of heavy metals except Cr and Ni in their soft tissues than in their shells (Cd: $2.10{\sim}3.16$, Cu: $19.73{\sim}28.66$, Pb: $0.67{\sim}1.17$, Zn: $216.1{\sim}285.7\;{\mu}g/g$ dry weight in the soft tissues; Cr: $1.19{\sim}2.58$, Ni: $0.47{\sim}1.16\;{\mu}g/g$ dry weight in the shells). Differences in the Cd, Cu, Ni and Pb concentrations in O. hirasei soft tissues reflected differences in heavy metal concentrations in the sediments at the sampling sites. The coefficients of variation for Cd, Cu and Pb were lower than those for other metals in the soft tissues. Levels of Cd in the tissues of O. hirasei were the highest among the metals examined in this study. Therefore, the soft tissue of O. hirasei appears to be a promising bioindicator particularly for Cd.

화합물 반도체 Cu(InGa)Se2박막 태양전지의 제작과 태양광발전 활용

  • Kim, Je-Ha;Jeong, Yong-Deok;Bae, Seong-Beom;Park, Rae-Man;Han, Won-Seok;Jo, Dae-Hyeong;Lee, Jin-Ho;Lee, Gyu-Seok;Kim, Yeong-Seon;O, Su-Yeong
    • Proceedings of the Materials Research Society of Korea Conference
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    • 2009.05a
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    • pp.8.2-8.2
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    • 2009
  • 구리(Cu)-인듐(In)-갈륨(Ga)-셀레늄(Se)의 4 원소 화합물 반도체인 Cu(InGa)$Se_2$ (CIGS) 태양전지 세계 최고 셀효율은 2008년 현재 19.9% 로서 박막형 태양전지 중 가장 높은 효율을 보이고 있다. 이는 다결정(폴리) 실리콘 태양전지의 20.3%와 대등한 수준이다. 이 CIGS 태양전지는 제조단가를 표준 결정형 실리콘 태양전지 대비 50% 대로 획기적으로 낮출 수 있어 가장 경쟁력이 있는 차세대 재료로 꼽히고 있다. 본 연구에서는 CIGS태양전지를 고진공 물리 증작법으로 제작하였으며 표면과 박막의 순도를 외부오염을 방지하기 위하여 후면전극, 광흡수체 및 전면전극을 동일 진공에서 제작할 수 있는 멀티 챔버 클러스터 증착 시스템을 이용하였다. 기판으로 소다라 임유리, 후면전극으로 Mo, 전면전극으로 I-ZnO/Al:ZnO 및 ITO를 이용하였다. 버퍼층으로 CdS를 chemical bath deposition (CBD)를 이용하였다. 소자는 무반사막을 사용하지 않고 Al/Ni전극 그리드를 이용하였다. 이 소자로부터 0.22 $cm^2$에서 16%의 효율을 얻었다. 각 박막층 간 계면의 분석을 전기적인 특성, ellisometry에 의한 광특성, 표면과 결정성에 대한 SEM 및 XRD의 특성을 보고한다. 또한, 대표적 화합물 반도체 박막 태양전지인 CIGS 태양전지의 기술의 현황, 학문적인 과제 및 실용화의 문제점을 발표하기로 한다.

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Study of the Influence of Heavy Metal Ions(Cu, Cr, Pb, Zn) on Biochemical Oxygen Demand (BOD 測定에 影響을 미치는 重金屬이온에 關한 연구)

  • Choi, Taek-Pyul;Yun, O-Sub
    • Journal of Environmental Health Sciences
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    • v.9 no.2
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    • pp.75-81
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    • 1983
  • The Biochemical Oxygen Demand(BOD) indicates that microbes are proliferating or that oxygen is being spent by breathing action when examining water under the same aerobic condition. In this research of the mesurement of BOD are the poisonous elements of heavy metal ions such as Cu-ion, Cr-ion, Pb-ion and Zn-ion. They exert an unfavorable influence in the analysis of BOD and research was performed to provide certain data of minimum negative influence by the poisonous matters. The results of the research confirm that heavy metal ion(Cu, Cr, Pb, Zn) do direct an influence upon the normal growth of aerobic microbes in actual tests of chemical analysis of portable water or sewage. The most critical concentration for a negative effect on lowering oxygen quantity and disturbing the aerobic mocrobes normal growth was found to be 0.01 mg/l. Therefore, test results are not valid if the heavy metal concentration is to or greater than 0.0mg/l, To improve comprehension through out the research the author uses the following abbreviations: 1. The Cu-ion is to be excluded before experimental analysis if it is over 0.01mg/l inorder to obtain a real value for the BOD. 2. The Cr-ion is to be excluded before experimental analysis if it is over 0.01mg/l in order to obtain a real value for the BOD. 3. The Pb-ion is to be excluded before experimental analysis if it is over 0.01mg/l in order to obtain a real value for the BOD. 4. The Zn-ion is to be excluded before experimental analysis if it is over 0.01mg/l in order to obtain a real value for the BOD.

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