• Title/Summary/Keyword: Carrier concentration and mobility

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Transparent MWCNT Thin Films Fabricated by using the Spray Method (스프레이법으로 제작된 투명 MWCNT 박막)

  • Jang, Kyung-Uk
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.23 no.4
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    • pp.338-342
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    • 2010
  • Carbon nanotubes (CNTs) have excellent electrical, chemical stability, mechanical and thermal properties. The MWCNT films were investigated as a transparent electrode for the solar cell, OLED, and field-emission display. MWCNT films were fabricated by air spray method, whose process is quite low-costed, using the multi-walled CNTs solution on glass substrates. Moreover, the most stable film was fabricated when the spraying time was 60 sec. The film that was sprayed with the MWCNT dispersion for 60 sec, has 300nm thick. And its electric resistivity, transmittance rate, mobility and carrier concentration are $6{\times}10^{-2}{\Omega}{\cdot}cm$, 50% at ${\lambda}=550mm$, $4.3{\times}10^{-2}cm^2/V{\cdot}s$ and $2.1{\times}10^{21}cm^{-3}$, respectively. Also, absorption energy of MWCNT films show from 3.9 eV to 4.6 eV. Furthermore, we can use MWCNT films fabricated by the spray method for the transparent electrode.

Application of Al-doped Zinc Oxide for transparent conductive thin film (Al이 첨가된 Zinc Oxide박막의 투명전도막으로서의 응용)

  • 정운조;정용근;유용택
    • Electrical & Electronic Materials
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    • v.8 no.6
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    • pp.693-698
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    • 1995
  • We fabricated Zinc Oxide transparent conductive thin films with 2wt% of A1203 doping using rf magnetron sputtering. And we investigated electrical and optical characteristics of them which were made with conditions ; rf power 60-300W, thickness of film 3000 11000.angs.. Resistivity, carrier concentration and Hall mobility were investigated for electrical characteristics. Transmittance and optical band gap were investigated with Spectrophotometer in the wavelength range between 200-900 nm. As a result, ZnO thin film fabricated with rf power of 180W and thickness of 5000.angs. showed the best properties. At the best condition, the sample has resistivity of 1*10$\^$-4/.ohm.cm and transmittance of 95% in the visible range.

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Al-doped ZnO via Sol-Gel Spin-coating as a Transparent Conducting Thin Film

  • Nam, Gil-Mo;Kwon, Myoung-Seok
    • Journal of Information Display
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    • v.10 no.1
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    • pp.24-27
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    • 2009
  • A simple nonalkoxide sol-gel route for depositing an Al-doped ZnO thin film on a glass substrate was derived in this study. The initial Al dopant concentration in the sol-gel preparation varied and ranged from 0 to 5%. The sol-gel-derived thin films showed c-plane preferred crystallization of their hexagonal phase, with nanosized grain structures. First and second post-heat-treatments were carried out to improve the film’s electrical resistivity. The carrier density and the Hall mobility were measured and discussed to explain the electrical resistivity. The optical transmittance within the visible range showed compatible properties, which indicates the possible use of A1-doped ZnO as a transparent electrode in flat panel displays.

Structure and Electrical Properties of P-doped ZnO Thin Films with Annealing Temperatures (열처리 온도에 따른 P-doped ZnO 박막의 구조적 및 전기적 특성)

  • Han, Jung-Woo;Yoon, Yung-Sup;Kang, Seong-Jun;Joung, Yang-Hee
    • Proceedings of the IEEK Conference
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    • 2008.06a
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    • pp.501-502
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    • 2008
  • In this study, P-doped ZnO thin films were prepared on sapphire substrates by pulsed laser deposition and annealing method. The electrical properties were investigated as a function of annealing temperatures at a fixed oxygen pressure. The XRD measurement showed that p-doped ZnO thin films were c-axis oriented. The Hall measurement showed that p-type ZnO thin film was observed. The carrier concentration of $1.18{\times}10^{16}cm^{-3}$ and the mobility of $0.96\;cm^{-3}/Vs$ were obtained for the P-doped ZnO thin film fabricated annealing temperature $850^{\circ}C$.

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Effects of Sputter Pressure on the Properties of Sputtered ZnO:Al Films Deposited on Plastic Substrate (플라스틱 기판에 증착한 ZnO:Al 박막의 특성에 미치는 스퍼터 압력 효과)

  • Lee, Jae-Hyeong
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.22 no.3
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    • pp.277-283
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    • 2009
  • In this paper, aluminum doped zinc oxide (ZnO:Al) thin films on plastic substrate such as poly carbonate (PC), polyethylene terephthalate (PET) were prepared by RF magnetron sputtering method for flexible solar cell applications. Effects of the sputter pressure on the structural, electrical and optical properties were investigated. The crystallinity and the degree of the (002) orientation were deteriorated with increasing the sputter pressure. When the sputter pressure was higher, the conductivity of ZnO:Al films was improved because of the high carrier concentration and the Hall mobility. High quality ZnO:Al films with resistivity as low as $1.9{\times}10^{-3}{\Omega}-cm$ and the optical transmittance over 80 % in the visible region have been obtained on PC substrate at 2 mTorr.

Vapor Phase Epitaxial Growth and Properties of GaN (GaN의 기상성장과 특성)

  • 김선태;문동찬
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1996.05a
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    • pp.72-75
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    • 1996
  • A hydride vapor phase epitaxy (HVPE) method is performed to prepare the GaN thin films on c-plane sapphire substrate. The full-width at half maximum of double crystal X-ray rocking curves from 20$\mu\textrm{m}$-thick GaN was 576 arcsecond. The photoluminescence spectrum measured 10 K shows the hallow bound exciton (I$_2$) line and weak donor-acceptor peak, however, there was not observed deep donor-acceptor pair recombination indicate the GaN crystals prepared in this study are of high purity and high crystalline quality. The GaN layer is n-type conducting with electron mobility of 72 $\textrm{cm}^2$/V$.$sec and with carrier concentration of 6 x 10$\^$18/cm/sup-3/.

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Influence of Plasma Discharge Power on the Electrical and Optical Properties of Aluminum Doped Zinc Oxide Thin Films

  • Moon, Yeon-Keon;Park, Jong-Wan
    • Korean Journal of Materials Research
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    • v.16 no.6
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    • pp.346-350
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    • 2006
  • Al-doped ZnO (AZO) thin films were grown on type of glass#1737 substrates by DC magnetron sputtering. The structural, electrical and optical properties of the films were investigated as a function of various plasma discharge power. The obtained films were polycrystalline with a hexagonal wurtzite structure and preferentially oriented in the (002) crystallographic direction. The lowest resistivity was $6.0{\times}10^{-4}{\Omega}cm$ with the carrier concentration of $2.69{\times}10^{20}cm^{-3}$ and Hall mobility of 20.43 $cm^2/Vs$. The average transmittance in the visible range was above 90%.

Characterization of F- and Al-codoped ZnO Transparent Conducting Thin Film prepared by Sol-Gel Spin Coating Method

  • Nam, Gil Mo;Kwon, Myoung Seok
    • Journal of the Korean Ceramic Society
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    • v.53 no.3
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    • pp.338-342
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    • 2016
  • ZnO thin film co-doped with F and Al was prepared on a glass substrate via simple non-alkoxide sol-gel spin coating. For a fixed F concentration, the addition of Al co-dopant was shown to reduce the resistivity mainly due to an increase in electrical carrier density compared with ZnO doped with F only, especially after the second post-heat-treatment in a reducing environment. There was no effective positive contribution to the reduction in resistivity due to the mobility enhancement by the addition of Al co-dopant. Optical transmittance of the ZnO thin film co-doped with F and Al in the visible light domain was shown to be higher than that of the ZnO thin film doped with F only.

Oxidative Modification of Human Ceruloplasmin by Methylglyoxal: An in vitro study

  • Kang, Jung-Hoon
    • BMB Reports
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    • v.39 no.3
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    • pp.335-338
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    • 2006
  • Methylglyoxal (MG) is an endogenous physiological metabolite which is present in increased concentrations in diabetics. MG reacts with the amino acids of proteins to form advanced glycation end products. In this in vitro study, we investigated the effect of MG on the structure and function of ceruloplasmin (CP) a serum oxidase carrier of copper ions in the human. When CP was incubated with MG, the protein showed increased electrophoretic mobility which represented the aggregates at a high concentration of MG (100 mM). MG-mediated CP aggregation led to the loss of enzymatic activity and the release of copper ions from the protein. Radical scavengers and copper ion chelators significantly prevented CP aggregation. CP is an important protein that circulates in plasma as a major copper transport protein. It is suggested that oxidative damage of CP by MG may induce perturbations of the copper transport system and subsequently lead to harmful intracellular condition. The proposed mechanism, in part, may provide an explanation for the deterioration of organs in the diabetic patient.

Design of Thermoelectric Films for Micro Generators (마이크로 발전기의 열전박막 설계)

  • Kim, Hyun-Se;Lee, Yang-Lae;Lee, Kong-Hoon
    • Proceedings of the KSME Conference
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    • 2007.05a
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    • pp.1455-1458
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    • 2007
  • In this research, a polycrystalline silicon (poly-Si) film layer for micro thermoelectric generator (TEG) was fabricated. The fabrication process of the thermoelectric poly-Si film layer is explained. The P-type and N-type poly-Si films were fabricated on a tetra ethoxy silane (TEOS) layer with a supporting Si wafer. Seebeck coefficient and electrical conductivity were measured, including the transport properties such as the hall coefficient, hall mobility and carrier concentration. The design parameters for a rapid thermal process (RTP) were decided based on the experimental results. The measured power factors of the P-type and N-type were $21.2\;{\mu}Wm^{-1}K^{-2}$ and $26.7\;{\mu}Wm^{-1}K^{-2}$, respectively.

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