• Title/Summary/Keyword: Semiconducting Materials

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Direct Writing of Semiconducting Oxide Layer Using Ink-Jet Printing

  • Lee, Sul;Jeong, Young-Min;Moon, Joo-Ho
    • 한국정보디스플레이학회:학술대회논문집
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    • 2007.08a
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    • pp.875-877
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    • 2007
  • Zinc tin oxide (ZTO) sol-gel solution was synthesized for ink-jet printable semiconducting ink. Bottom-contact type TFT was produced by printing the ZTO layer between the source and drain electrodes. The transistor involving the ink-jet printed ZTO had the $mobility\;{\sim}\;0.01\;cm^2V^{-1}s^{-1}$. We demonstrated the direct-writing of semiconducting oxide for solution processed TFT fabrication.

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Sensing performances of Semiconducting Carbon Nanomaterials based Gas Sensors Operating at Room Temperature (반도체 탄소 나노재료 기반 상온 동작용 가스센서)

  • Choi, Sun-Woo
    • Ceramist
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    • v.22 no.1
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    • pp.96-106
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    • 2019
  • Semiconducting carbon-based nanomaterials including single-walled carbon nanotubes(SWCNTs), multi-walled CNT(MWCNTs), graphene(GR), graphene oxide(GO), and reduced graphene oxide(RGO), are very promising sensing materials due to their large surface area, high conductivity, and ability to operate at room temperature. Despite of these advantages, the semiconducting carbon-based nanomaterials intrinsically possess crucial disadvantages compared with semiconducting metal oxide nanomaterials, such as relatively low gas response, irreversible recovery, and poor selectivity. Therefore, in this paper, we introduce a variety of strategies to overcome these disadvantages and investigate principle parameters to improve gas sensing performances.

Specific Heat and Thermal Conductivity Measurement of CNT/EEA Semiconducting Materials and XLPE Insulator (CNT/EEA 반도전층 재료와 XLPE 절연체의 열적 특성)

  • Yang, Jong-Seok;Lee, Kyoung-Yong;Shin, Dong-Hoon;Park, Dae-Hee
    • The Transactions of the Korean Institute of Electrical Engineers C
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    • v.55 no.11
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    • pp.514-519
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    • 2006
  • To improve the mean-life and the reliability of power cable, we have investigated specific heat (Cp) and thermal conductivity of XLPE insulator and semiconducting materials in 154[kV] underground power transmission cable. Specimens were made of sheet form with the seven of specimens for measurement. Specific heat (Cp) and thermal conductivity were measured by DSC (Differential Scanning Calorimetry) and Nano Flash Diffusivity. Specific-heat measurement temperature ranges of XLPE insulator were from $20[^{\circ}C]\;to\;90[^{\circ}C]$, and the heating rate was $1[^{\circ}C/min]$. And the measurement temperatures of thermal conductivity were $25[^{\circ}C],\;55[^{\circ}C]\;and\;90[^{\circ}C]$. In case of semiconducting materials, the measurement temperature ranges of specific heat were from $20[^{\circ}C]\;to\;60[^{\circ}C]$, and the heating rate was $1[^{\circ}C/min]$. And the measurement temperatures of thermal conductivity were $25[^{\circ}C]\;and\;55[^{\circ}]C$. From these experimental results both specific heat and thermal conductivity were increased by heating rate because volume of materials was expanded according to rise in temperature. We could know that a small amount of CNT has a excellent thermal properties.

Specific Heat and Thermal Conductivity Measurement of XLPE Insulator and Semiconducting Materials (XLPE 절연층과 반도전층 재료의 비열 및 열전도 측정)

  • Lee Kyoung-Yong;Yang Jong-Seok;Choi Yong-Sung;Park Dae-Hee
    • The Transactions of the Korean Institute of Electrical Engineers C
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    • v.55 no.1
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    • pp.6-10
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    • 2006
  • To improve mean-life and reliability of power cable, we have investigated specific heat (Cp) and thermal conductivity of XLPE insulator and semiconducting materials in 154(kV) underground power transmission cable. Specimens were respectively made of sheet form with EVA, EEA and EBA added $30[wt\%],$ carbon black, and the other was made of sheet form by cutting XLPE insulator in 154(kV) power cable. Specific heat (Cp) and thermal conductivity were measured by DSC (Differential Scanning Calorimetry) and Nano Flash Diffusivity. Specific-heat measurement temperature ranges of XLPE insulator were from $20[^{\circ}C]\;to\;90[^{\circ}C],$ and the heating rate was $1[^{\circ}C/mon].$ And the measurement temperatures of thermal conductivity were $25[^{\circ}C],\;55[^{\circ}C]\;and\;90[^{\circ}C].$ In case of semiconducting materials, the measurement temperature ranges of specific heat were from $20[^{\circ}C]\;to\;60[^{\circ}C],$ and the heating rate was $1[^{\circ}C/mon].$ And the measurement temperatures of thermal conductivity were $25[^{\circ}C],\;55[^{\circ}C].$ In addition we measured matrix of semiconducting materials to show formation and growth of carbon black in base resins through the SEM. From these experimental results, both specific heat and thermal conductivity were increased by heating rate because volume of materials was expanded according to rise in temperature.

Synthesis of Semiconducting $KTaO_3$ Thin films (KTaO3 Thin Film의 Semiconducting 합성)

  • Koo, Ja-Yl;Ohm, Woo-Yong;Ahn, Chang-Hwan;Bae, Hyung-Jin
    • Proceedings of the IEEK Conference
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    • 2006.06a
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    • pp.981-982
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    • 2006
  • In this study, the synthesis and semiconducting properties of cation and defect-doped KTaO3 film is reported. KTaO3is an important material for optoelectronic and tunable microwave applications. It is an incipient ferroelectric with a cubic structure that becomes ferroelectric when doped with Nb. the films were grown on (001) MgO single crystal substrates using pulsed-laser deposition. Semiconducting behavior is achieved by inducing oxygen vacancies in the KTaO3 lattice via growth in a hydrogen atmosphere. The resistivity of semiconducting KTaO3:Ca films was as low as 10cm, and n-type semiconducting behavior was indicated. Hall mobility and carrier concentration were 0.27 cm2/Vs and 3.21018cm-3.

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Modulus Properties and Smoothness Measurement of Semiconducting Materials Using the DMA and SEM (DMA와 SEM을 사용한 반도전층 재료의 탄성특성과 평활도 측정)

  • Yang, Jong-Seok;Lee, Kyoung-Yong;Choi, Yong-Sung;Park, Dae-Hee
    • The Transactions of the Korean Institute of Electrical Engineers C
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    • v.54 no.10
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    • pp.443-448
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    • 2005
  • To measure modulus, damping properties and smoothness of semiconducting materials in power cable, we have investigated those of semiconducting materials showed by changing the content of carbon black. Then they were produced as sheets after pressing for 20 minutes at 180[$^{\circ}C$] with a pressure of 200[kg/cm$^{2}$]. The content of conductive carbon black was the variable, and their contents were 20, 30 and 40[wt$\%$], respectively. The modulus and tans were measured by DMA 2980. The ranges of measurement temperature were from -50[$^{\circ}C$] to 100[$^{\circ}C$] and measurement frequency was 1[Hz3. The modulus of specimens was increased according to a increment of a carbon black content. And modulus was rapidly decreased at the glass transition temperature. The tans of specimens was decreased according to a increment of a carbon black content. The smoothness was measured by JSM-6400. EEA resin from SEM measurement was best the dispersion of carbon back in base resin.

Mechanical and Thermal Properties Changes of Nano Semiconducting Materials due to Addition of Carbon Nanotubes (탄소나노튜브를 첨가한 나노 반도전층 재료의 기계적/열적 특성 변화 연구)

  • Yang, Jong-Seok;Lee, Kyoung-Yong;Shin, Dong-Hoon;Choi, Yu-Jin;Park, Noh-Joon;Park, Dae-Hee
    • Proceedings of the KIEE Conference
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    • 2006.10a
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    • pp.28-29
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    • 2006
  • To improve Mechanical and Thermal Properties of semiconducting materials in power cable, we have investigated those of semiconducting materials showed by changing the content of carbon black and Carbon Nanotube. Density were measured by EW-200SG. High temperature, heat degradation initiation temperature, and heat weight loss were measured by TGA (Thermogravimetric Analysis). The dimension of measurement temperature was $0[^{\circ}C]$ J to $700[^{\circ}C]$, and rising temperature was $10[^{\circ}C/min]$. Heat degradation initiation temperature from the TGA results was decreased according to increasing the content of Carbon Nanotube. That is, heat stabilities of EVA containing the weak VA (vinyl acetate) against heat was measured the lowest. From the results of the experiment applied in this study, it is evident that a small amount of Carbon nanotube additives significantly improved the Mechanical and Thermal Properties of semiconducting materials.

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Synthesis of Semiconducting $KTaO_3$ Thin films

  • Bae, Hyung-Jin;Ku, Jayl;Ahn, Tae-Won;Lee, Won-Seok
    • Proceedings of the IEEK Conference
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    • 2005.11a
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    • pp.1265-1268
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    • 2005
  • In this study, the synthesis and semiconducting properties of cation and defect-doped $KTaO_3$ film is reported. $KTaO_3$ is an important material for optoelectronic and tunable microwave applications. It is an incipient ferroelectric with a cubic structure that becomes ferroelectric when doped with Nb. While numerous studies have investigated the thin-film growth of semiconducting perovskites, little is reported about semiconducting $KTaO_3$ thin films. In this work, the films were grown on (001) MgO single crystal substrates using pulsed-laser deposition. Semiconducting behavior is achieved by inducing oxygen vacancies in the $KTaO_3$ lattice via growth in a hydrogen atmosphere. The resistivity of semiconducting $KTaO_3:Ca$ films was as low as 10cm, and n-type semiconducting behavior was indicated. Hall mobility and carrier concentration were $0.27cm^2/Vs$ and $3.21018cm^{-3}$, respectively. Crystallinity and microstructure of the $KTaO_3:Ca$ films were examined using X-ray diffraction and field-emission scanning microscopy.

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Numerical Analysis of Loss Power Properties in the Near-Field Electromagnetic Wave Through A Microstrip Line for Multilayer Magnetic Films with Different Levels of Electrical Conductivity

  • Lee, Jung-Hwan;Kim, Sang-Woo
    • Journal of Magnetics
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    • v.13 no.3
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    • pp.92-96
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    • 2008
  • There are few reports of high frequency loss behavior in the near-field for magnetic films with semiconducting properties, even though semiconducting magnetic materials, such as soft magnetic amorphous alloys and nanocrystalline thin films, have been demonstrated. The electromagnetic loss behavior of multilayer magnetic films with semiconducting properties on the microstrip line in quasi-microwave frequency band was analyzed numerically using a commercial finite-element based electromagnetic solver. The large increase in the absorption performance and broadband characteristics of the semiconducting/insulating layer magnetic films examined in this study were attributed to an increase in the loss factor of resistive loss. The electromagnetic reflection increased significantly with increasing conductivity, and the loss power deteriorated significantly. The numerical results of the magnetic field distribution showed that a strong radiated signal on the microstrip line was emitted with increasing conductivity and decreasing film thickness due to re-reflection of the radiated wave from the surface of the magnetic film, even though the emitted levels varied with film thickness.

Thermal Conductivity Characteristic of Carbon Nanotube Composites and XLPE Insulator (탄소나노튜브 복합체와 XLPE 절연체의 열전도도 특성)

  • Yang, Jong-Seok;Kook, Jeong-Ho;Park, Noh-Joon;Nah, Chang-Woon;Park, Dae-Hee
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2006.11a
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    • pp.160-161
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    • 2006
  • To Improve the mean-life and the reliability of power cable, we have investigated thermal conductivity of XLPE insulator and semiconducting materials in l54[kV] underground power transmission cable. Specimens were made of sheet form with the nine of specimens for measurement. Thermal conductivity were measured by Nano Flash Diffusivity thermal conductivity measurement temperature ranges of XLPE insulator were from 20[$^{\circ}C$] to 90[$^{\circ}C$], and the heating rate was 1[$^{\circ}C$/mm]. In case of semiconducting materials. the measurement temperature ranges of thermal conductivity were from 20[$^{\circ}C$] to 60[$^{\circ}C$], and the heating rate was 1[$^{\circ}C$/min].

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