• Title/Summary/Keyword: Electronic and thermal properties

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Effect of the top coating surface tension and thermal expansion matching on the electrical properties of single-walled carbon nanotube network films (표면장력과 열팽창계수 불일치가 단일벽 탄소나노튜브 필름의 전도성에 미치는 영향 연구)

  • Kim, Jun-Suk;Han, Joong-Tark;Jeong, Hae-Deuk;Jeong, Hee-Jin;Jeong, Seung-Yol;Lee, Geon-Woong
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2010.03b
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    • pp.42-42
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    • 2010
  • We have characterized the previously undescribed parameters for engineering the electrical properties of single-walled carbon nanotube (SWCNT) films for technological applications. The surface tension of the top coating passivation material and matching coefficients of thermal expansion for the substrate and carbon nanotube network are two crucial parameters for the fabrication of reliable and highly conductive single-walled carbon nanotube network thin films.

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Effect of the top coating surface tension and thermal expansion matching on the electrical properties of single-walled carbon nanotube network films (표면장력과 열팽창계수 불일치가 단일벽 탄소나노튜브 필름의 전도성에 미치는 영향 연구)

  • Kim, Jun-Suk;Han, Joong-Tark;Jeong, Hee-Jin;Jeong, Seung-Yol;Lee, Geon-Woong
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2010.06a
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    • pp.278-278
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    • 2010
  • We have characterized the previously undescribed parameters for engineering the electrical properties of single-walled carbon nanotube (SWCNT) films for technological applications. The surface tension of the top coating passivation material and matching coefficients of thermal expansion for the substrate and carbon nanotube network are two crucial parameters for the fabrication of reliable and highly conductive single-walled carbon nanotube network thin films.

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First-principles Calculations of the Phonon Transport in Carbon Atomic Chains Based on Atomistic Green's Function Formalism

  • Kim, Hu Sung;Park, Min Kyu;Kim, Yong-Hoon
    • Proceedings of the Korean Vacuum Society Conference
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    • 2014.02a
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    • pp.425.1-425.1
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    • 2014
  • Thermal transport in nanomaterials is not only scientifically interesting but also technological important for various future electronic, bio, and energy device applications. Among the various computation approaches to investigate lattice thermal transport phenomena in nanoscale, the atomistic nonequilibrium Green's function approach based on first-principles density functional theory calculations appeared as a promising method given the continued miniaturization of devices and the difficulty of developing classical force constants for novel nanoscale interfaces. Among the nanometerials, carbon atomic chains, namely the cumulene (all-doulble bonds, ${\cdots}C=C=C=C{\cdots}$) and polyyne (alternation of single and triple bonds, ${\cdots}C{\equiv}C-C{\equiv}C{\cdots}$) can be considered as the extream cases of interconnction materials for nanodevices. After the discovery and realization of carbon atomic chains, their electronic transport properties have been widely studied. For the thermal transport properties, however, there have been few literatures for this simple linear chain system. In this work, we first report on the development of a non-equilibrium Green's function theory-based computational tool for atomistic thermal transport calculations of nanojunctions. Using the developed tool, we investigated phonon dispersion and transmission properties of polyethylene (${\cdots}CH2-CH2-CH2-CH2{\cdots}$) and polyene (${\cdots}CH-CH-CH-CH{\cdots}$) structures as well as the cumulene and polyyne. The resulting phonon dispersion from polyethylene and polyene showed agreement with previous results. Compared to the cumulene, the gap was found near the ${\Gamma}$ point of the phonon dispersion of polyyne as the prediction of Peierls distortion, and this feature was reflected in the phonon transmission of polyyne. We also investigated the range of interatomic force interactions with increase in the size of the simulation system to check the convergence criteria. Compared to polyethylene and polyene, polyyne and cumulene showed spatially long-ranged force interactions. This is reflected on the differences in phonon transport caused by the delicate differences in electronic structure.

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Improvement of Carrier Mobility on Silicon-Germanium on Insulator MOSFET Devices with a Strained-Si Layer

  • Cho, Won-Ju;Koo, Hyun-Mo;Lee, Woo-Hyun;Koo, Sang-Mo;Chung, Hong-Bay
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.20 no.5
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    • pp.399-402
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    • 2007
  • The effects of heat treatment on the electrical properties of strained-Si/SiGe-on-insulator (SGOI) devices were examined. We proposed the optimized heat treatment processes for improving the back interfacial electrical properties in SGOI-MOSFET. By applying the additional pre-RTA (rapid thermal annealing) before gate oxidation step and the post-RTA after source/drain dopant activation step, the electrical properties of strained-Si channel on $Si_{1-x}Ge_x$ layer were greatly improved, which resulting the improvement of the driving current, transconductance, and leakage current of SGOI-MOSFET.

A Study on Properties of C-V of Silicone Rubber due to Electrode Materials (전극재에 의한 실리콘 고무의 C-V 특성에 관한 연구)

  • Lee, Sung Ill
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.28 no.11
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    • pp.721-726
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    • 2015
  • In this study, the properties of C-V degradation for thermal conductivity silicone rubber sample which is attached by copper-copper, copper-aluminum, aluminum-aluminum on upper-side and under-side has been measured at temperature of $80^{\circ}C{\sim}140^{\circ}C$. The results of this study are as follows. In case the frequency is increased, it found that the electrostatic capacity increased with increasing temperature to $80^{\circ}C$, $110^{\circ}C$, $140^{\circ}C$ regardless of kind of electrode. It found that the electrostatic capacity increased with becoming high temperature range of frequency regardless of kind of electrode. This result is considered to be caused by thermal absorption on the thermal conductivity silicone rubber sample. It found that the electrostatic capacity decreased with increasing temperature and frequency. This result is considered to be caused by molecular motion of C-F radical or OH radical.

Effects of MnO$_2$additives on the thermal properties of infrared radiator of Cordierite system (Cordierite계 적외선 방사체의 열적 특성에 미치는 MnO$_2$의 영향)

  • 송창열;강이국;최두선;신용덕
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1994.05a
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    • pp.133-137
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    • 1994
  • Infrared radiator of Cordierite system were manufactured using Cordierite(2Mgo$.$2Al$_2$O$_3$$.$5SiO$_2$) and Clay 30wt% as main materials and addition of MnO$_2$ from 0. 1 to 2 5wt% of Dry pressing and slip casting The effects of MnO$_2$ additives on the thermal properties of infrared radiator of Cordierite system. The more the thermal expansion could be lowered the more the amount (wt%) of additives MnO$_2$is increased in the below 4.5$\mu\textrm{m}$. The high efficiency Infrared radiator of Cordierite system using dry pressing method when the amount of additives MnO$_2$is 2.0 wt%

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Evaluations of Sb20Se80-xGex (x = 10, 15, 20, and 25) Glass Stability from Thermal, Structural and Optical Properties for IR Lens Application

  • Jung, Gun-Hong;Kong, Heon;Yeo, Jong-Bin;Lee, Hyun-Yong
    • Journal of the Korean Ceramic Society
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    • v.54 no.6
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    • pp.484-491
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    • 2017
  • Chalcogenide glasses have been investigated in their thermodynamic, structural, and optical properties for application in various opto-electronic devices. In this study, the $Sb_{20}Se_{80-x}Ge_x$ with x = 10, 15, 20, and 25 were selected to investigate the glass stability according to germanium ratios. The thermal, structural, and optical properties of these glasses were measured by differential scanning calorimetry (DSC), X-ray diffraction (XRD), and UV-Vis-IR Spectrophotometry, respectively. The DSC results revealed that $Ge_{20}Sb_{20}Se_{60}$ composition showing the best glass stability theoretically results due to a lower glass transition activation energy of 230 kJ/mol and higher crystallization activation energy of 260 kJ/mol. The structural and optical analyses of annealed thin films were carried out. The XRD analysis reveals obvious results associated with glass stabilities. The values of slope U, derived from optical analysis, offered information on the atomic and electronic configuration in Urbach tails, associated with the glass stability.

Electrical Properties of MOS Devices by Rapid Thermal Nitridation(RTN) (RTN에 의해 제작된 MOS소자의 전기적 특성)

  • Chang, Eui-Gu;Choi, Won-Bun;Lee, Cheol-In
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1988.05a
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    • pp.24-26
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    • 1988
  • The electrical properties of thin nitrided thermal oxides prepared by rapid thermal nitridation(RTN) have been studied. The flatband voltages were calculated using C-V measurement and found to vary as nitridation time and temperature. After nitridation an increase in the fixed oxide charge density was always observed, but the distribution of it as a function of annealing time was found to be random. The breakdown voltages were measured using curve tracer.

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Growth and Properties of Ultra-thin SiO2 Films by Rapid Thermal Dry Oxidation Technique (급속 건식 열산화 방법에 의한 초박막 SiO2의 성장과 특성)

  • 정상현;김광호;김용성;이수홍
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.17 no.1
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    • pp.21-26
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    • 2004
  • Ultra-thin silicon dioxides were grown on p-type(100) oriented silicon employing rapid thermal dry oxidation technique at the temperature range of 850∼1050 $^{\circ}C$. The growth rate of the ultra-thin film was fitted well with tile model which was proposed recently by da Silva & Stosic. The capacitance-voltage, current-voltage, characteristics were used to study the electrical properties of these thin oxides. The minimum interface state density around the midgap of the MOS capacitor having oxide thickness of 111.6 $\AA$ derived from the C-V curve was ranged from 6 to 10${\times}$10$^{10}$ /$\textrm{cm}^2$eV.

The Study on Thermal Properties of Sleeve with Various Defects (시공유형에 따른 가공송전선 접속개소의 열적 특성 분석 연구)

  • Ahn, Sang-Hyun;Kim, Byung-Geol;Kim, Sang-Shu;Shon, Hong-Kwan;Park, In-Pyo;Kim, Sung-Kyu
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2008.11a
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    • pp.461-461
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    • 2008
  • According to previous report, aged sleeves for old transmission lines have various defect such as biased installation or corrosion of steel sleeve. These defects occupied almost 50 percent of investigated aged sleeves. The defects have been limited power capacity of transmission line. And it can cause serious problems such as rapid increasing of sag or falling out of overhead conductor from sleeve. This paper study on thermal behavior of sleeve with various defect model. The detailed results were presented in the text.

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