• 제목/요약/키워드: XPS (X-ray Photoelectron Spectroscopy)

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Reaction of NO on Vanadium Oxide Surfaces: Observation of the NO Dimer Formation

  • Jeong, Hyun-Suck;Kim, Chang-Min
    • Bulletin of the Korean Chemical Society
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    • v.28 no.3
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    • pp.413-416
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    • 2007
  • The adsorption and surface reactions of NO on a VO/V(110) surface have been investigated using X-ray photoelectron spectroscopy (XPS), near-edge X-ray absorption fine structure, and temperature programmed desorption (TPD) technique. NO is molecularly adsorbed on VO/V(110) at 80 K. As the surface coverage of NO increases, the NO dimer is formed on the surface at 80 K. Both NO and (NO)2 are adsorbed on the surface with the N-O bond perpendicular to the surface. (NO)2 decomposes at ~100 K and the reaction product is desorbed as N2O. Decomposition of NO takes place when the surface temperature is higher than 273 K.

Effects of Oxygen on the Properties of Mg-doped Zinc Tin Oxide Films Prepared by rf Magnetron Sputtering (rf 마그네트론 스퍼터링으로 증착한 Mg-doped Zinc Tin Oxide막의 특성에 미치는 산소의 영향)

  • Park, Ki Cheol;Ma, Tae Young
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.26 no.5
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    • pp.373-379
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    • 2013
  • Mg-doped zinc tin oxide (ZTO:Mg) thin films were prepared on glasses by rf magnetron sputtering. $O_2$ was introduced into the chamber during the sputtering. The optical properties of the films as a function of oxygen flow rate were studied. The crystal structure, elementary properties, and depth profiles of the films were investigated by X-ray diffraction (XRD), x-ray photoelectron spectroscopy (XPS), and secondary ion mass spectrometry (SIMS), respectively. Bottom-gate transparent thin film transistors were fabricated on $N^+$ Si wafers, and the variation of mobility, threshold voltage etc. with the oxygen flow rate were observed.

Effect of the Substrate Temperature on the Copper Oxide Thin Films

  • Park, Ju-Yeon;Gang, Yong-Cheol
    • Proceedings of the Korean Vacuum Society Conference
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    • 2010.08a
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    • pp.71-71
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    • 2010
  • Copper oxide thin films were deposited on the p-type Si(100) by r.f. magnetron sputtering as a function of different substrate temperature. The deposited copper oxide thin films were investigated by atomic force microscopy (AFM), scanning electron microscopy (SEM), spectroscopic ellipsometry (SE), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). The SEM and SE data show that the thickness of the copper oxide films was about 170 nm. AFM images show that the surface roughness of copper oxide films was increased with increasing substrate temperature. As the substrate temperature increased, monoclinic CuO (111) peak appeared and the crystal size decreased while the monoclinic CuO (-111) peak was independent on the substrate temperature. The oxidation states of Cu 2p and O 1s resulted from XPS were not affected on the substrate temperature. The contact angle measurement was also studied and indicated that the surface of copper oxide thin films deposited high temperature has more hydrophobic surface than that of deposited at low temperature.

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$CdCl_2$ 활성화 공정과 후면 산화막 제거 공정을 거친 CdTe 박막의 표면 물성 변화 연구

  • Cheon, Seung-Ju;Lee, Seung-Hun;Jeong, Yeong-Hun;Bae, Jong-Seong;Kim, Ji-Hyeon;Kim, Dong-Hwan
    • Proceedings of the Materials Research Society of Korea Conference
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    • 2012.05a
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    • pp.98.1-98.1
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    • 2012
  • CdS/CdTe 박막 태양전지의 경우 높은 광흡수 계수를 가지고 있는 CdTe 다결정 박막을 흡수층으로이용 한다. CdTe 다결정 박막의 경우 CdS/CdTe 계면과 박막 내부에 많은 결함들이 존재 하며, CdTe 박막 내부에 존재하는 캐리어의 수를 증가 시키기 위하여 $CdCl_2$ 활성화 공정을 거치게 된다. 이때 박막의 물성 변화를 분석 하기 위하여, X-Ray Diffractometer (XRD), X-ray Photoelectron Spectroscopy (XPS)를 이용하여 박막 표면 분석을 진행 하였다. 이를 통해 박막 표면에서 산소가 Cd와 Te과 결합하면서 산화막이 생성되는 것을 확인하였다. 박막 표면에 생성된 산화막은 후면 금속 전극 형성을 위해, 용액 공정을 통하여 제거 되는데, 이때 CdTe 박막 표면에서 Cd이 용액에 의해 제거 되는 것을 확인 하였다.

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Interaction of SO2 with Oxygen on Ni(100) Studied by XPS and NEXAFS

  • Kim, Chang-Min
    • Bulletin of the Korean Chemical Society
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    • v.27 no.12
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    • pp.2037-2039
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    • 2006
  • The adsorption and surface reactions of $SO_2$ on Ni(100), c($2{\times}2$)_O/Ni (100) and NiO(111)/Ni(100) surfaces have been investigated using X-ray photoelectron spectroscopy (XPS) and near-edge X-ray absorption fine structure (NEXAFS) technique. On Ni(100), chemisorbed $SO_2$ is formed at 160 K. When $SO_2$ is adsorbed on c($2{\times}2$)_O/Ni(100) at 160 K, $SO_2$ reacts with oxygen to form $SO_3$ and trace amount of $SO_4$ species. $SO_3$ is adsorbed on this surface with its $C_3$ axis perpendicular to the surface. On a NiO(111)/Ni(100) surface, both $SO_3$ and $SO_4$ species are formed at 160 K from adsorbed $SO_2$.

Synthesis and Photoactivity of SnO2-Doped TiO2 Thin Films (SnO2가 도핑된 TiO2 박막의 합성 및 광촉매 효과)

  • Jung, Mie-Won;Kwak, Yun-Jung
    • Journal of the Korean Ceramic Society
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    • v.44 no.11
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    • pp.650-654
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    • 2007
  • [ $SnO_2$ ]-doped $TiO_2$ thin films were prepared from tin (IV) bis (acetylacetonate) dichloride and titanium diisopropoxide bis (acetylacetonate) with pluronic P123 or degussa P25 as a structural-directing agent. These hydrolyzed sol were spin coated onto Si(100) wafer substrate. The microstructure, morphology and bonding states of thin films were studied by field-emission scanning electron microscopy (FE-SEM), X-ray diffractometry (XRD), and X-ray photoelectron spectroscopy (XPS). The photocatalytic activity of these films was investigated by using indigo carmine solution.

Spectroscopic and Morphological Investigation of Co3O4 Microfibers Produced by Electrospinning Process

  • Baek, J.H.;Park, J.Y.;Hwang, A.R.;Kang, Y.C.
    • Bulletin of the Korean Chemical Society
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    • v.33 no.4
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    • pp.1242-1246
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    • 2012
  • The Co oxide microfibers were synthesized using the electrospinning process and formed $Co_3O_4$ microfibers after being calcined at high temperatures. The calcination temperature influenced the diameters, morphology, crystalline phase, and chemical environment of the fibers. The surface morphology of the obtained fibers was examined by using the scanning electron microscope (SEM). As the calcination temperatures increased from room temperature to 873 and 1173 K, the diameters of the cobalt oxide fibers decreased from 1.79 to 0.82 and 0.32 mm, respectively. The structure of the fibers was investigated with X-ray diffraction (XRD) and transmission electron microscopy (TEM). The calcined $Co_3O_4$ fibers had crystalline face-centered cubic (fcc) structure. The X-ray photoelectron spectroscopy (XPS) results revealed that increasing the calcination temperature promoted the formation of $Co^{2+}$ and $Co^{3+}$ species.

Surface Characteristics of Copper Oxide Thin Films with Different Oxygen Ratio

  • Park, Ju-Yeon;Jo, Jun-Mo;Gang, Yong-Cheol
    • Proceedings of the Korean Vacuum Society Conference
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    • 2010.02a
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    • pp.385-385
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    • 2010
  • Copper oxide thin films were deposited on the p-type Si(100) by r.f. magnetron sputtering as a function of different oxygen concentration. The deposited copper oxide thin films were investigated by atomic force microscopy (AFM), scanning electron microscopy (SEM), spectroscopic ellipsometry (SE), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). The SEM and SE data show that the thickness of the copper oxide films was in the range of 100-400 nm. AFM images show that the surface morphology was depended on the oxygen ratio. The crystal structure of copper oxide films was changed from metallic copper to copper oxide with increasing oxygen concentration. The oxidation states of Cu 2p and O 1s resulted from XPS were consistent with XRD results.

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A surface chemical analysis strategy for the microstructural changes in a CuAgZrCr alloy cast under oxidation conditions

  • Ernesto G. Maffia;Mercedes Munoz;Pablo A. Fetsis;Carmen I. Cabello;Delia Gazzoli;Aldo A. Rubert
    • Advances in materials Research
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    • v.13 no.2
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    • pp.141-151
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    • 2024
  • The aim of this work was to determine the behavior of alloy elements and compounds formed during solidification in the manufacturing process of the CuAgZrCr alloy under an oxidizing environment. Bulk and surface analysis techniques, such as Scanning Electron Microscopy (SEM), X-ray Photoelectron Spectroscopy (XPS), Raman and X-ray diffraction (XRD) were used to characterize the phases obtained in the solidification process. In order to focus the analysis on the on grain boundary interface, partial removal of the matrix phase by acid attack was performed. The compositional differences obtained by SEM-EDX, Raman and XPS on post-manufacturing materials allowed us to conclude that the composition of grain boundaries of the alloy is directly influenced by the oxidizing environment of alloy manufacturing.

Surface Characterization of Zinc Selenide Thin Films Obtained by RF co-sputtering

  • Lee, Seokhee;Kang, Jisoo;Park, Juyun;Kang, Yong-Cheol
    • Journal of the Korean Chemical Society
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    • v.66 no.5
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    • pp.341-348
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    • 2022
  • In this work, radio frequency magnetron sputtering was used to deposit zinc selenide thin films on p-type silicon (100) wafers and glass substrates in a high vacuum chamber. Several surface characterization instruments were implemented to study the thin films. X-ray photoelectron spectroscopy results revealed that oxidized Zn bound to Se (Zn-Se) at 1022.7 ± 0.1 eV becomes the dominant oxidized species when Se concentration exceeds 70%. Scanning electron microscopy coupled with energy dispersive spectroscopy showed that incorporating Se in Zn thin films will lead to formation of ZnSe grains on the surface. Contact angle measurements indicated that ZnSe-60 exhibited the lowest total surface free energy value of 24.94 mN/m. Lastly, ultraviolet-visible spectrophotometry and ultraviolet photoelectron spectroscopy data evinced that the energy band gap gradually increases with increasing Se concentration with ZnSe-70 having the highest work function value of 4.91 eV.