• Title/Summary/Keyword: CD structure

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The Study on the Reliability Improvement of Bibliographic Database Using CD-ROM - With a Special Emphasis on Download and Upload - (CD-ROM을 이용(利用)한 서지정보(書誌情報) 데이터베이스의 신뢰성향상(信賴性向上) 기법연구(技法硏究) - 다운로드와 업로드를 중심(中心)으로 -)

  • Kim, Chang-Keun;Shin, Yong-Ju
    • Journal of Information Management
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    • v.20 no.2
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    • pp.69-99
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    • 1989
  • With regard to system configuration, file structure and function, this study has compared and analyzed KITLAS developed by KIT Library and CD-ROM BiblioFile, which is selected among CD-ROM Catalog Production Products, the mass storage media, produced by the fast-growing laser technology and information technology. Furthurmore, this study illuminates how to improve the reliability of bibliographic database, implementing downloading and uploading processes which make possible the conversion and online, mass transmission of CD-ROM MARC records at once.

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CdSe/$TiO_2$ electrode of photoelectrochemical[PEC] cell for hydrogen production from water using solar energy (태양광과 물로부터 수소생산을 위한 광전기화학전지의 CdSe/$TiO_2$ 전극)

  • Lee, Eun-Ho;Jung, Kwang-Deog;Joo, Oh-Shim
    • Transactions of the Korean hydrogen and new energy society
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    • v.16 no.2
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    • pp.130-135
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    • 2005
  • Cadmium selenide is one of the group IIb-VI compounds, which is the promising semiconductor material due to its wide range of technological applications in optoelectronic devices such as photoelectrochemical cells, solid state solar cells, thin film photoconductors etc. CdSe has optical band gap of 1.7-1.8eV and proper conduction band edge for water splitting. CdSe films are coated with small thickness(20-50nm) nanocrystalline $TiO_2$ film by electrodeposition or chemical bath deposition methods and PEC properties of CdSe and CdSe/$TiO_2$ sandwich structure are studied. The photoactivity of CdSe and CdSe/$TiO_2$ films deposited on titanium substrate is studied in aqueous electrolyte of 1M NaOH solution. Photocurrent and photovoltage obtained were of the order of 2-4 mA/$cm^2$ and 0.5V, respectively, under the intensity of illumination of 100 mW/$cm^2$.

Novel Fabrication of CdS Hollow Spheres Induced by Self-assembled Process

  • Choi, Kyoung-Hoon;Chae, Weon-Sik;Jung, Jin-Seung;Kim, Yong-Rok
    • Bulletin of the Korean Chemical Society
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    • v.30 no.5
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    • pp.1118-1120
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    • 2009
  • Micro-size CdS spheres of hollow shape were fabricated through the self-assembly of high density arrow-like nanorods. The synthesis of the CdS hollow spheres were accomplished in an aqueous solution of cadmium nitrate and triblock copolymer (Pluronic P123) at low temperature (80 ${^{\circ}C}$) through the slow release of S2- ions from thioacetamide. Morphology of the fabricated CdS hollow spheres was characterized by X-ray diffraction (XRD), field-emission scanning electron microscopy (FE-SEM), and transmission electron microscopy (TEM). The results indicate that the arrow-like CdS nanorods are simultaneously grown and attached each other to form the building units that become the spheres with hollow inside as a self-assembled process. The CdS spheres have a diameter of $2{\sim}3 {\mu}m$ and consist of the nanorods with a length of$\sim$800 nm. The nanocrystal building blocks have a hexagonal CdS structure.

A Polycrystalline CdZnTe Film and Its X-ray Response Characteristics for Digital Radiography

  • Kim, Jae-Hyung;Park, Chang-Hee;Kang, Sang-Sik;Nam, Sang-Hee
    • Transactions on Electrical and Electronic Materials
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    • v.4 no.5
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    • pp.15-18
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    • 2003
  • The Cd$\_$1-x/Zn$\_$x/Te film was produced by thermal evaporation for the flat-panel X-ray detector. The crystal structure and the surface morphology of poly crystalline Cd$\_$1-x/Zn$\_$x/Te film were examined using XRD and SEM, respectively. The leakage current and X-ray sensitivity of the fabricated films were measured to analyze the X-ray response characteristic of Zn in a polycrystalline CdZnTe thin film. The leakage current and the output charge density of Cd$\_$0.7/Zn$\_$0.3/Te thin film were measured to 0.3 1nA/$\textrm{cm}^2$ and 260 pC/$\textrm{cm}^2$ at an applied voltage of 2.5 V/$\mu\textrm{m}$, respectively. Experimental results showed that the increase of Zn doping rates in Cd$\_$1-x/Zn$\_$x/Te detectors reduced the leakage current and improved the X-ray sensitivity significantly. The leakage current was drastically diminished by the formation of thin parylene layer in the Cd$\_$0.7/Zn$\_$0.3/Te detector.

Patterning issues for the fabrication of sub-micron memory capacitors′ electrodes (초미세 메모리 커패시터의 전극형성을 위한 식각 기술)

  • 김현우
    • Proceedings of the Materials Research Society of Korea Conference
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    • 2003.11a
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    • pp.160-160
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    • 2003
  • This paper describes some of the key issues associated with the patterning of metal electrodes of sub-micron (especially at the critical dimension (CD) of 0.15 $\mu\textrm{m}$) dynamic random access memory (DRAM) devices. Due to reactive ion etching (RIE) lag, the Pt etch rate decreased drastically below the CD of 0.20 $\mu\textrm{m}$ and thus the storage node electrode with the CD of 0.15 $\mu\textrm{m}$ could not be fabricated using the Pt electrodes. Accordingly, we have proposed novel techniques to surmount the above difficulties. The Ru electrode for the stack-type structure is introduced and alternative schemes based on the introduction of the concave-type structure using Pt or Ru as an electrode material are outlined.

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A Study on the Electrical and Optical Properties of CdS Thin Film by Annealing for Solar Cell (태양전지용 CdS 박막의 열처리에 따른 전기 및 광학적 특성에 관한 연구)

  • Park, Jung-Cheul;Chu, Soon-Nam
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.22 no.11
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    • pp.999-1003
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    • 2009
  • In this paper, CdS thin films well-known to window layer for solar cell were fabricated by means of vacuum evaporation method treated with different substrate heating. During film fabrication the substrates were heated at 50, 75 and $100^{\circ}C$, respectively. The thin films were then annealed at $200^{\circ}C$ in atmosphere, and the electrical and optical properties were investigated. By annealing, the hexagonal structure of films was changed into cubic structure. Their transmissivity was also increased and moved to longer wave band. It was shown that the film fabricated with the substrate heat-treated at $50^{\circ}C$ had the lowest resistivity.

Properties of high efficiency 2-${\lambda}$ white organic light emitting diode (고 효율 2파장 백색 유기 발광 소자의 발광 특성)

  • Lee, Oun-Gyu;Oh, Young-Jun;Ko, Young-Wook
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2006.11a
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    • pp.324-325
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    • 2006
  • In order to develop high efficiency white organic light-emitting diodes (OLEDs), OLED devices consisted of red and blue emitting layers (EMLs) were fabricated and the effect of respective layer thickness and the order of layer stacking on the luminous efficiency was evaluated Red/blue structure showed higher efficiency than blue/red, due to the higher exiton formation. In the blue layer of red/blue structure. However, the efficiency of the red/blue significantly depended on the thickness of the red layer, whereas the thickness of the blue layer was not affect so much. The optimum thickness of the red layer was 20 ${\AA}$, where the luminous and power efficiencies were 155 cd/A and 10.51 lm/W at 1000~3000$cd/m^2$ respectively and the maximum luminance was about 80,000 $cd/m^2$.

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Correlation between host materials and device performances of phosphorescent white organic light-emitting diodes with blue/orange/blue stacked emitting structure

  • Joo, Chul-Woong;Kim, Sung-Hyun;Yook, Kyoung-Soo;Jeon, Soon-Ok;Lee, Jun-Yeob
    • 한국정보디스플레이학회:학술대회논문집
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    • 2008.10a
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    • pp.439-442
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    • 2008
  • A mixed host structure of TCTA and TPBI was used in orange emitting layer and host composition was critical to device performances of PHWOLEDs. PHWOLEDs with TPBI host in orange emitting layer showed high quantum efficiency of 10.3 % at $1000\;cd/m^2$ with little change of CIE coordinates of (0.32, 0.34) from $100\;cd/m^2$ to $10,000\;cd/m^2$.

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Synthesis and Molecular Structure of Macrocyclic Chlorotetraamine Cadmium(II) Complex (거대고리 Chlorotetraamine Cadmium(II) 착물의 합성과 분자 구조)

  • 최기영;서일환;추금홍
    • Korean Journal of Crystallography
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    • v.11 no.3
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    • pp.133-136
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    • 2000
  • The molecular structure of [Cd(L)Cl]Cl·2H₂O(1)(L=3,14-dimethyl-2,6,13,17-tetraazatricyclo[14,4,0/sup 1.18/,0/sup 7.12/]docosane) has been determined by X-ray diffraction. Crystallographic dta for 1: triclinic space group P1, a=9.671(1), b=10.784(1), c=12.679(2)Å, α=112.31(1), β=99.49(1), γ=93.95(1)°, V=1230.6(3)ų, Z=2, R=0.0779. The coordination of the cadmium atom is a distorted square-pyramid with four secondary amines of the macrocycle occupying the basal sites (Cd-N/sub av/=2.300(3)Å) and a terminal chlorine atom at the axial position with a Cd-Cl(1) distance of 2.463(2)Å.

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