• Title/Summary/Keyword: bilayer

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Soft X-ray Spectroscopy of ClAlPc/Pentacene/ITO Interfaces: Role of ClAlPc on Energetic Band Alignment

  • Kim, Min-Su;Heo, Na-Ri;Lee, Sang-Ho;Jo, Sang-Wan;Smith, Kevin E.
    • Proceedings of the Korean Vacuum Society Conference
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    • 2014.02a
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    • pp.190.1-190.1
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    • 2014
  • The interfacial electronic structure of a bilayer of chloroaluminum phthalocyanine (ClAlPc) and pentacene grown on indium tin oxide (ITO) has been studied using synchrotron radiation-excited photoelectron spectroscopy. The energy difference between the highest occupied molecular orbital (HOMO) level of the pentacene layer and the lowest unoccupied molecular orbital (LUMO) level of the ClAlPc layer (EDHOMO - EALUMO) was determined and compared with that of C60/pentacene bilayers. The EDHOMO - EALUMO of a heterojunction with ClAlPc was found to be 1.4 eV, while that with C60 was 1.0 eV. This difference is discussed in terms of the difference of the ionization energy of each acceptor materials. We also obtained the complete energy level diagrams of ClAlPc/pentacene/ITO and C60/pentacene/ITO, respectively.

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Investigation of Thin Film Structures of Cobalt Silicides Formed with a Co Monolayer and a Co/Ti Bilayer (Co 단일층과 Co/Ti 이중층에 의하여 형성된 코발트 실리사이드막의 구조)

  • Lee, Jong-Mu;Lee, Byeong-Uk;Gwon, Yeong-Jae;Kim, Yeong-Uk;Lee, Su-Cheon
    • Korean Journal of Materials Research
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    • v.6 no.9
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    • pp.861-870
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    • 1996
  • Co 단일층과 Co/Ti 이중층으로부터 형성된 코발트 실리사이드를 최종 막의 구조와 에피텍셜 성장 측면에서 조사하였다. Co 단일층은 그 두께와는 관계없이 전체 막이 CoSi2로 변화된 반면에, Co/Ti 이중층 구조에서는 Co와 Ti 막의 두께비가 최종막 구조에 상당한 영향을 주었다. 그리고 CoSi2막의 에피 성장이 Co 단일층에서 보다는 Co/Ti 이중층에서 보다 용이하였다.

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Microstructural Observation of Cu/Cr Multilayers by Heat Treatment (열처리에 따른 Cu/Cr 다층 박막의 미세 조직 관찰)

  • 양혁수;김기범
    • Journal of Surface Science and Engineering
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    • v.28 no.6
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    • pp.376-385
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    • 1995
  • Copper-chromium multilayers with a nominal bilayer thickness of about 400 $\AA$ (200 $\AA$ each) were prepared by dc magnetron sputtering and the evolution of microstructure during heat treatment was investigated by using x-ray diffractometry(XRD), Auger electron spectroscopy(AES) and transmission electron microscopy(TEM). It was observed that an amorphous phase with a thickness of about 40 $\AA$ was formed at the interfaces of the as-deposited Cu/Cr multilayered film using cross-sectional TEM. At elevated temperatures, the Cu(111) reflection showed increasing intensity and decreasing line-width as a result of copper grain growth. The intermixed amorphous phase disappeared after annealing at $250^{\circ}C$ for 1 h and the multilayer structure was stable up to $400^{\circ}C$ for 1 h annealing. At $600^{\circ}C$ annealing, it was observed that the multilayer structure was completely destroyed and copper and chromium phases were fully intermixed.

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Simulations of premixed combustion in porous media (다공판 내의 예혼합연소 특성 해석)

  • Shin, Youngjun;Lee, Jeongwon;Kim, Yongmo
    • 한국연소학회:학술대회논문집
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    • 2012.04a
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    • pp.253-255
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    • 2012
  • This study has numerically investigated the combustion processes in the bilayer porous media. To account for the velocity transition and diffusion influenced by solid matrix, porosity effects are included in the governing equations. Heat transfer coefficient is calculated by Nusselt number to reflect the effect of gas velocity, pore diameter, and material properties. Numerical results indicate that the present approach is capable of the essential features of the premixed combustion in the porous burner, in terms of the precised flame structure, pollutant formation, and flame stabilization. It is also found that heat transferred from the downstream flame zone is conducted to the upstream flame region through the solid matrix and the preheated mixture. By increasing the inlet velocity, the solid temperature of upstream is cooling down.

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Layer-by-layer self-assembly colorant multi-layer preparation using natural colorant Berberine and anionic polyelectrolyte (베르베린 천연색소화합물과 음이온고분자전해질을 이용한 layer-by-layer self-assembly 색소다층박막 제조)

  • Son Young-A;Park Young-Min;Lee Seung-Goo;Ravikumar K.
    • Textile Coloration and Finishing
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    • v.18 no.1
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    • pp.28-32
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    • 2006
  • A multi-layer of the dye, natural colorant Berberine, was successfully developed by the self-assembly deposition from water-soluble cationic dye(Berberine chloride) and anionic polyelectrolyte PSS(Polysodium 4-styrenesulfonate) in aqueous solution via electrostatic attraction. The corresponding results on multi-layer were characterized by UV-Vis absorbance measurements. The growth of multi-layer formed by the sequential interaction was also determined. The findings measured by UV-Vis spectrophotometer showed that the bilayer deposition characteristic was linear and highly reproducible from layer to layer.

Interfacial Reactions of Cu/$CoSi_2$ and Cu/Co-Ti Bilayer Silicide (Cu/$CoSi_2$ 및 Cu/Co-Ti 이중층 실리사이드의 계면반응)

  • Lee, Jong-Mu;Lee, Byeong-Uk;Kim, Yeong-Uk;Lee, Su-Cheon
    • Korean Journal of Materials Research
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    • v.6 no.12
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    • pp.1192-1198
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    • 1996
  • 배선 재료나 salicide 트랜지스터에 적용될 것으로 기대되는 Cu 배선과 Co 단일층 및 Co/Ti 이중층을 사용하여 형성된 코발트 실리사이드간의 열적 안정성에 대하여 조사하였다. 40$0^{\circ}C$열처리후 Cu3Si 막이 CoSi2층과 Si 기판 사이에 형성되었는데, 이것은 Cu 원자의 확산에 기인한 것이다. $600^{\circ}C$에서의 열처리 후에 형성된 최종막의 구조는 각각 Cu/CoSi2/Cu3Si/Si과 TiO2/Co-Ti-Si 합금/CoSi2/Cu3Si/Si였으며, 상부에 형성된 TiO2층은 산소 오염에 의한 것으로 밝혀졌다.

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A study on the formation of epitaxial $CoSi_{2}$thin film using Co/Refractory metal bilayer (코발트/내열금속 이중박막을 이용한 $CoSi_{2}$ 에피박막형성에 관한 연구)

  • Kim, Jong-Ryeol;Jo, Yun-Seong;Bae, Gyu-Sik
    • Korean Journal of Materials Research
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    • v.5 no.3
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    • pp.324-332
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    • 1995
  • 전자빔 증착법을 사용하여 Ti과 Co를 Si(100) 단결정, 다결정 Si 및 Si$O_{2}$기판에 증착한 후 90$0^{\circ}C$에서 20초 급속 열처리하여, Co/Ti 이중박막으로부터의 실리사이드화 반응을 조사하였다. 단결정 시편의 경우 Ti의 두께를 5~6mm로 최소화함으로서 두께가 균일하고 기판과의 계면이 평탄하며 비저항이 낮고 열적 안정성이 높은 Co$Si_{2}$ 에피박막을 형성할 수 있었다. 그러나 다결정 시편에는 두께와 계면이 불균일하고 열적으로도 불안정한 다결정의 Co$Si_{2}$와 그 위에 두개의 Co-Ti-Si혼합층이 형성되었다. 한편 Si$O_{2}$ 우에 증착된 Co/Ti은 열처리를 하여도 확산하지 않고 그대로 남아 있어서, Co/Ti 이중박막의 Si$O_{2}$와의 반응성이 미약함을 보여 주었다.

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Low-voltage Organic Thin-film Transistors with Polymeric High-k Gate Insulator on a Flexible Substrates (고유전율 절연체를 활용한 저 전압 유연 유기물 박막 트랜지스터)

  • Kim, Jae-Hyun;Bae, Jin-Hyuk;Lee, In-ho;Kim, Min-Hoi
    • Journal of Sensor Science and Technology
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    • v.24 no.3
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    • pp.165-168
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    • 2015
  • We demonstrated low-voltage organic thin-film transistors (OTFTs) with bilayer insulators, high-k polymer and low temperature crosslinkable polymer, on a flexible plastic substrate. Poly (vinylidene fluoridetrifluoroethylene) (P(VDF-TrFE)) and poly (2-vinylnaphthalene) are used for high-k polymer gate insulator and low temperature crosslinkable polymer insulators, respectively. The mobility of flexible OTFTs is $0.17cm^2/Vs$ at gate voltages -5 V after bending operation.

Thermal Behavior of the Layered Structure in Metal-dodecanesulfonate intercalation compounds, [M($H_2O$)$_6$](C$_12$H$_25$SO$_3$)$_2$.x$H_2O$ (M=Co, Cu) (도데칸술폰이 삽입된 금속 화합물, [M($H_2O$)$_6$(C$_12$H$_25$SO$_3$)$_2$.x$H_2O$ (M=Co, Cu)의 층상 구조의 열적 성질)

  • 허영덕;박성훈;전태현
    • Journal of Surface Science and Engineering
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    • v.33 no.1
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    • pp.25-33
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    • 2000
  • The synthesis and characterization of intercalated compound of dodecanesulfornate into hydrated metal, [M($H_2$O)\ulcorner](C\ulcornerH\ulcorner$SO_3$)$_2$.$xH_2$O (M=Co, Cu) was presented. The compounds shows a layered structure which was determined by powder X-ray diffraction. Thermal behavior of the layered structure was investigated using thermal analysis, and FT-IR spectroscopy by varying the temperature. The increase in layer spacing of the products by increasing the temperature is also checked by X-ray diffraction. We can suggest three kinds of layered structure by varying the temperature, which is accompanied by changing the intercalated dodecanesulfonate from the monolayer to the bilayer structure or changing the tilt angle.

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The Fabrication and Characterization of the Photovoltaic Cells Composed of Polydiacetylene and Fullerene

  • Song Jeong-Ho;Kang Tae-Jo;Cho Young-Don;Lee Sun-Hyoung;Kim Jeong-Soo
    • Fibers and Polymers
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    • v.7 no.3
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    • pp.217-222
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    • 2006
  • Propargyl alcohol was coupled to 2,4-hexadiyne-1,6-diol (HDD) and crystallized in the process of ultraviolet irradiation-induced topochemical polymerization. The HDD polymer crystals were used as one component in the fabrication of organic photovoltaic cells, in combination with fullerene as the electron acceptor. The various structures of the produced photovoltaic cells included bilayer, trilayer, and bulk heterojunction structures. Their photovoltaic properties were analyzed in relation to crystal structure, electrochemical properties, and band structure of the HOD polydiacetylene polymers.