• Title/Summary/Keyword: Epitaxial film

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Optical properties of epitaxial $Gd_2$O_3:EU^{3+}$luminescent thin films depending on crystallinity ($Gd_2$O_3:EU^{3+}$ 형광체 박막의 결정성에 따른 발광특성 연구)

  • 장문형;최윤기;정권범;황보상우;장홍규;노명근;조만호;손기선;김창해
    • Journal of the Korean Vacuum Society
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    • v.12 no.4
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    • pp.275-280
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    • 2003
  • Epitaxial Gd$_2O_3:Eu^{3+}$luminescent thin films have been grout on Si(III) substrates using ionized Cluster Beam Deposition (ICBD). After the film growing, they were implanted and post annealed to change the crystal structure. The initial growth stage was monitored by using in-situ Reflection High Energy Electron Diffraction (RHEED). The formed crystal structure was identified with X-ray diffraction (XRD) technique and Fourier transform infrared (FT-R) spectroscopy. The electronic states variations were investigated by Near Edge X-ray Absorption Fine Structure (NEXAFS). Photoluminescence (PL), Cathodoluminescence (CL). and Vacuum ultraviolet (VUV) spectrum were used for examining the optical properties. We report the optical property changes depending on crystal structure and the electronic states.

Doping-free Transparent Conducting Schottky Type Heterojunction Solar Cells

  • Kim, Joon-Dong
    • Proceedings of the Korean Vacuum Society Conference
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    • 2012.02a
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    • pp.209-209
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    • 2012
  • High-efficient transparent conductive oxide (TCO) film-embedding Si heterojunction solar cells were fabricated. An additional doping was not applied for heterojunction solar cells due to the spontaneous junction formation between TCO films and an n-type Si substrate. Three different TCO coatings were formed by sputtering method for an Al-doped ZnO (AZO) film, an indium-tin-oxide (ITO) film and double stacks of ITO/AZO films. An improved crystalline ITO film was grown on an AZO template upon hetero-epitaxial growth. This double TCO films-embedding Si heterojunction solar cell provided significantly enhanced efficiency of 9.23% as compared to the single TCO/Si devices. The effective arrangement of TCO films (ITO/AZO) provides benefits of a lower front contact resistance and a smaller band offset to Si leading enhanced photovoltaic performances. This demonstrates a potential scheme of the effective TCO film-embedding heterojunction Si solar cells.

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Epitaxial growth of silicon thin films on insulating ($CeO_2$/Si) substrates (절연체 ($CeO_2$/Si)위에 성장된 실리콘 박막의 특성 연구)

  • 양지훈;문병식;김관표;김종걸;정동근;노용한;박종윤
    • Journal of the Korean Vacuum Society
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    • v.8 no.3B
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    • pp.322-326
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    • 1999
  • We have investigated the growing process of a silicon film on the $CeO_2/Si$ surface. The silicon was deposited by using electron beam deposition method. The $CeO_2$(111) film was grown on a (111)-oriented silicon substrate at $700^{\circ}C$ at oxygen [partial pressure of $5\times10^{-5}$ Torr. To investigate the condition of epitaxial growth of si films on the $CeO_2/Si$ substrate, we deposited Si at various temperature니 The overlayer silicon was characterized by using x-ray diffraction(XRD). double crystal x-ray diffraction (DCXRD), and transmission electron microscopy (TEM). At temperature higher than $690^{\circ}C$, $CeO_2$ layer was observed at the $CeO_2/Si$ interface, which was formed by chemical reaction with silicon and oxygen dissociated from $CeO_2$. When silicon was deposited on the $CeO_2/Si$ at $620^{\circ}C$, silicon grew epitaxially along the (111)-direction.

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YBCO coated conductor with a single $Y_2$O$_3$ buffer layer on biaxially textured Ni and NiW substrates

  • D. Q. Shi;R. K. Ko;K. J. Song;J. K. Chung;H. S. Ha;Kim, H. S.;Park, C.
    • Progress in Superconductivity and Cryogenics
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    • v.6 no.2
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    • pp.7-10
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    • 2004
  • A study regarding the epitaxial growth of single $Y_2O_3$ buffer layer on biaxially textured Ni and NiW substrates using pulsed laser deposition is presented. Different deposition conditions were employed and compared in order to obtain good epitaxial $Y_2O_3$ film, furthermore importantly, to obtain good YBCO superconducting films. Following YBCO film deposited by PLD on the top of $Y_2O_3$ films have a good structure and superconducting properties. The J$_{c}$ of YBCO films on $Y_2O_3$ /Ni and $Y_2O_3$ /NiW were $1.0{\times}10^6 A/cm^2 and 1.1\times}10^6 A/cm^2$<.TEX> at 77K and self-field respectively, which indicated that $Y_2O_3$ is a suitable candidate as a single buffer layer for the fabrication of YBCO coated conductor.r.