• Title/Summary/Keyword: As-deposited State

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Synthesis of rhombohedral-structured zinc germanate thin films and characteristics of divalent manganese-activated electroluminescence

  • Yoon, Kyung-Ho;Kim, Joo-Han
    • Proceedings of the Korean Vacuum Society Conference
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    • 2010.02a
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    • pp.453-453
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    • 2010
  • In this study, zinc germanate ($Zn_2GeO_4$) thin films has been synthesized by using radio frequency magnetron sputtering and the divalent manganese-activated luminescence was characterized. X-ray diffraction patterns of the as-deposited $Zn_2GeO_4$:Mn films showed only a broad feature, indicative of an amorphous structure. Scanning electron microscopy images revealed that the as-deposited $Zn_2GeO_4$:Mn has a smooth surface morphology. The $Zn_2GeO_4$:Mn films were found to be crystallized by annealing in air ambient at temperatures as low as $700^{\circ}C$. The annealed $Zn_2GeO_4$:Mn possessed a rhombohedral polycrystalline structure. The broad-band photoluminescent emission spectrum from 470 to 650nm was obtained at room temperature from the $Zn_2GeO_4$:Mn films. The emission peak was centered at around 535nm in the green range, which originates from the intrashell transition of manganese $3d^5$ electrons from $^4T_1$ excited-state level to the $^6A_1$ ground state. The PL emission spectrum had an asymmetric line shape, which results from the $^3d_5$ electron transitions of divalent manganese ions located at different sites of the zinc germanate host crystal lattice. Electroluminescent devices were fabricated using $Zn_2GeO_4$:Mn as an emission layer. The fabricated devices showed a green EL emission similar to the PL emission. The CIE chromaticity color coordinates of the EL emission were determined to be x=0.308 and y=0.657.

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Experimental Study on Pressures Changes on Infilling Soil and Geotextile Drain in Circular Acrylic Tube Structure (토사 주입과 배수 시 원형 아크릴 튜브 구조체의 압력 변화에 대한 실험적 연구)

  • Kim, Hyeong-Joo;Won, Myoung-Soo;Lee, Jang-Baek;Park, Tae-Woong
    • Journal of the Korean Society for Advanced Composite Structures
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    • v.6 no.3
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    • pp.86-94
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    • 2015
  • A series of injection and drainage test were conducted on an circular acrylic tube to investigate the pressure generated by the accumulated fill materials inside a circular acrylic tube structure. The acrylic tube was filled by means of gravity filling with a slurry material having an average water content of 700%. The water head during the filling process was 1.8m and the bottom pressure during initial filling was 20.18kPa. The recorded stress at the sides of the acrylic tube was 17.89kPa during the filling process and was reduced to 13.58kPa during the leaving process. Continuous drainage of the acrylic tube has greatly influenced the stresses around the tube structure. As the water is gradually allowed to overflow, the generated pressure at the topmost pressure sensor of the tube was reduced further to 2.17kPa. Eventually, the initially liquid state slurry material transforms into plastic state after water has dissipated and substantial soil particles are deposited in the acrylic tube. The final water content of the deposited silt inside the acrylic tube after the test was 42%. It was found that the state of stresses(geo-static earth pressures) in the acrylic tube was anisotropic rather than isotropic.

Distribution of Deposited Carbon in Carbon Brake Disc Made by Pressure-Gradient Chemical Vapor Infiltration

  • Chen, Jianxun;Xiong, Xiang
    • Carbon letters
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    • v.8 no.1
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    • pp.25-29
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    • 2007
  • The carbon brake discs were manufactured by densification the carbon fiber preform using PG-CVI technology with Propene as a carbon precursor gas and Nitrogen as a carrier gas. The densities of carbon brake discs were tested at different densification time. The results indicate that the densification rate is more rapid before 100 hrs than after 200 hrs. The CTscanning image and the SEM technology were used to observe the inner subtle structure. CT-images show the density distribution in the carbon brake disc clearly. The carbon brake disk made by PG-CVI is not very uniform. There is a density gradient in the bulk. The high-density part in the carbon brake is really located in the friction surface, especially in the part of inner circle. This density distribution is most suitable for the stator disc.

Structural and Electrical Properties of WOx Thin Films Deposited by Direct Current Reactive Sputtering for NOx Gas Sensor

  • Yoon, Young-Soo;Kim, Tae-Song;Park, Won-Kook
    • Journal of the Korean Ceramic Society
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    • v.41 no.2
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    • pp.97-101
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    • 2004
  • W $O_{x}$-based semiconductor type thin film gas sensor was fabricated for the detection of N $O_{x}$ by reactive d.c. sputtering method. The relative oxidation state of the deposited W $O_{x}$ films was approximately compared by the calculation of the difference of the binding energy between Ols to W4 $f_{7}$2/ core level XPS spectra in the standard W $O_3$ powder of known composition. As the annealing temperature increased from 500 to 80$0^{\circ}C$, relative oxygen contents and grain size of the sputtered films were gradually increased. As the results of sensitivity ( $R_{gas}$/ $R_{air}$) measurements for the 5 ppm N $O_2$ gas, the sensitivity was 110 and the sensor showed recovery time as fast as 200 s. The other sensor properties were examined in terms of surface microstructure, annealing temperature, and relative oxygen contents. These results indicated that the W $O_3$ thin film with well controlled structure is a good candidate for monitoring and controlling of automobile exhaust.haust.t.t.t.

Formation of hydrophilic polymer films by DC-plasma of monomer and reactive gases

  • Kim, Ki-Hwan;Park, Sung-Chang;doo-Jin choi;Jung, Hyung-Jin;Koh, Seok-Keun
    • Proceedings of the Korean Vacuum Society Conference
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    • 1999.07a
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    • pp.161-161
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    • 1999
  • In the field of material science, the interests and efforts to modify the surface of materials in agreement with the need of usage have been extensively increasing. he modification to improve the wettability of surface is very important is terms of adhesion, printing, etc. It is very difficult to modify metal surface into hydrophilic one. therefore, surfactant coating has been generally used in many cases. However, surfactant has disadvantages such as environmental problem, soluble in water. in this study, hydrophilic polymer films as alternative of surfactant were deposited on metal substrate by DC plasma polymerization. Hydrophilic polymer films deposited by DC plasma show many merits such as good wettability, stone adhesion to substrate, high resistance to most chemicals. Monomer gas and reactive gas were used as source plasma polymerization. Plasma polymerized films were fabricated with process parameters of deposition time, ratio of gas mixture, current, pressure, etc. Effects of these variables on wettability of plasma polymer films will be discussed. With XPS and FT-IR analyses of plasma polymeric films, the relation between wettability and chemical state of polymer films by DC plasma was investigated.

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The Electrical Conductivity and Electrochemical Characteristics of Amphiphilic Milecules Multilayer Film confined with Hetero Type (양친매성 다중층막의 전기적 도전성 및 전기적 특성)

  • 최인희;박수길;임기조;이주성
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1996.05a
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    • pp.269-272
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    • 1996
  • The electrochemical behavior of Ru complex and PD complex monolayer, deposited on conductive substrate by the Langmuir-Blodgett(LB) technique as monolayer and multilayer, has been studied by cyclic voltammetry. Monolayer films show stable reversible state. Atomic resolution imaging of LB highly-conductive, environmently stable organic films has been obtained by atomic force microscopy (AFM) showing their closely packed structure,

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A Study on Effects of the Non-Deposited Arbitral Award with the Competent Court (관할법원에 송부${\cdot}$보관되지 않은 중재판정의 효력)

  • Oh Chang-Seog
    • Journal of Arbitration Studies
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    • v.15 no.3
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    • pp.55-84
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    • 2005
  • The arbitral award is the decision of the arbitrators on the dispute that had been submitted to them by the parties, either under the arbitration clause providing for the determination of future disputes or under submission of an existing controversy. The arbitral award has the same effect between the parties as a final and binding court judgment. The arbitration award shall acquire, as soon as it is given and delivered to each parties, the authority of res judicata in respect of the dispute it settles. The validity of an award is a condition precent for its recognition or enforcement. The validity of an award depends on the provisions of the arbitration agreement including any arbitration rules incorporated in it, and the law which is applicable to the arbitration proceedings. Such provisions usually address both the form and the content of the award. As the 'form', requires article 32 of Arbitration Act of Korea that an arbitral award should, at least, (1) be made in writing and be signed by all arbitrators. (2) state the reasons upon which it is based unless the parties have agreed that it should not, (3) state its date and place of arbitration. There are some further requirement which may have to be observed before an award which has been made by a tribunal can be enforced. (4) The duly authenticated award signed by the arbitrators shall be delivered to each of the parties and the original award shall be sent to and deposited with the competent court, accompanied by a document verifying such delivery. This rule can be interpreted as if the deposit of an arbitral award with the competent court is always required as a condition for its validity or as a preliminary to its enforcement in Korea. However, we must regard this rule which requires the deposit of an arbitral award with court, as rule of order, but not as condition of its validity. Because that the date on which the award is delivered to each party is important as it will generally determine the commencement of time limits for the making of any appeal which may be available. Furthermore, the party applying for recognition or enforcement merely has to supply the appropriate court with the duly authenticated original award or a duly certified copy thereof, not any document which proves that an the arbitral award is sent to and deposited with the competent court. In order to avoid some confusion which can be caused by its interpretation and application, the Article 32 (4) of Arbitration Act of Korea needs to be abolished or at least modified.

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INVESTIGATIONS OF OXIDATIONS OF SnOx AND ITS CHANGES OF THE PROPERTIES PREPARED BDEPOSITIONY REACTIVE ION-ASSISTED

  • Cho, J.S.;Choi, W.K.;Kim, Y.T.;Jung, H.J.;Koh, S.K.
    • Journal of the Korean institute of surface engineering
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    • v.29 no.6
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    • pp.766-772
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    • 1996
  • Undoped $SnO_x$ thin films were deposited on Si(100) substrate by using reactive ioassisted deposition technique (R-IAD). In order to investigate the effect of initial oxygen content and heat treatment on the oxidation state and crystalline structure of tin oxide films, $SnO_x$ thin films were post-annealed at 400~$600^{\circ}C$ for 1 hr. in a vacuum ~$5 \times 10^{-3}$ -3/ Torr or were directly deposited on the substrate of $400^{\circ}C$ and the relative arrival ration ($Gamma$) of oxygen ion to Sn metal varied from 0.025 to 0.1, i.e., average impinging energy ($E_a$) form 25 to 100 eV/atom. As $E_a$ increased, the composition ratio of $N_ON{sn}$ changed from 1.25 to 1.93 in post-annealing, treatment and 1.21 to 1.87 in in-situ substrate heating. In case of post-annealing, the oxidation from SnO to $SnO_2$ was closely related to initial oxygen contents and post-annealing temperature, and the perfect oxidation of $SnO_2$ in the film was obtained at higher than $E_a$=75 eV/atom and $600^{\circ}C$. The temperature for perfect oxidation of $SnO_2$ was reduced as low as $400^{\circ}C$ through in-situ substrate heating. The variation of the chemical state of $SnO_x$ thin films with changing $E_a$'s and heating method were also observed by Auger electron spectroscopy.

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Heterojunction Solar Cell with Carrier Selective Contact Using MoOx Deposited by Atomic Layer Deposition (원자층 증착법으로 증착된 MoOx를 적용한 전하 선택 접합의 이종 접합 태양전지)

  • Jeong, Min Ji;Jo, Young Joon;Lee, Sun Hwa;Lee, Joon Shin;Im, Kyung Jin;Seo, Jeong Ho;Chang, Hyo Sik
    • Korean Journal of Materials Research
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    • v.29 no.5
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    • pp.322-327
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    • 2019
  • Hole carrier selective MoOx film is obtained by atomic layer deposition(ALD) using molybdenum hexacarbonyl[$Mo(CO)_6$] as precursor and ozone($O_3$) oxidant. The growth rate is about 0.036 nm/cycle at 200 g/Nm of ozone concentration and the thickness of interfacial oxide is about 2 nm. The measured band gap and work function of the MoOx film grown by ALD are 3.25 eV and 8 eV, respectively. X-ray photoelectron spectroscopy(XPS) result shows that the $Mo^{6+}$ state is dominant in the MoOx thin film. In the case of ALD-MoOx grown on Si wafer, the ozone concentration does not affect the passivation performance in the as-deposited state. But, the implied open-circuit voltage increases from $576^{\circ}C$ to $620^{\circ}C$ at 250 g/Nm after post-deposition annealing at $350^{\circ}C$ in a forming gas ambient. Instead of using a p-type amorphous silicon layer, high work function MoOx films as hole selective contact are applied for heterojunction silicon solar cells and the best efficiency yet recorded (21 %) is obtained.