• Title/Summary/Keyword: barrier height

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A Study on Influence of the Head Restraint Position on Neck Injury in Rear End Collision (후방 추돌시 머리지지대 위치에 따른 목상해 연구)

  • Choi, Dong-Won;Chun, Young-Bum;Park, In-Song
    • Transactions of the Korean Society of Automotive Engineers
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    • v.18 no.5
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    • pp.20-24
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    • 2010
  • The position of the automobile's head restraint is very important for the neck injury in rear end collision. This study is about influence of the head restraint height and distance on neck injury during rear end collision. The effects of the position have been evaluated experimentally. The neck injuries are calculated by the relative acceleration between the upper and lower neck. As a result, It is found that the head restraint should be close enough to the back of the head and high enough to the top of the head.

Study on DC Characteristics of 4H-SiC Recessed-Gate MESFETs (Recessed-gate 4H-SiC MESFET의 DC특성에 관한 연구)

  • Park, Seung-Wook;Hwang, Ung-Jun;Shin, Moo-Whan
    • Korean Journal of Materials Research
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    • v.13 no.1
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    • pp.11-17
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    • 2003
  • DC characteristics of recessed gate 4H-SiC MESFET were investigated using the device/circuit simulation tool, PISCES. Results of theoretical calculation were compared with the experimental data for the extraction of modeling parameters which were implemented for the prediction of DC and gate leakage characteristics at high temperatures. The current-voltage analysis using a fixed mobility model revealed that the short channel effect is influenced by the defects in SiC. The incomplete ionization models are found out significant physical models for an accurate prediction of SiC device performance. Gate leakage is shown to increase with the device operation temperatures and to decrease with the Schottky barrier height of gate metal.

Layered Silicate-Polymer Nanocomposites

  • Jeong, Han-Mo
    • Proceedings of the Materials Research Society of Korea Conference
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    • 2003.03a
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    • pp.18-18
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    • 2003
  • Natural clays are composed of oxide layers whose thickness is about 1nm and cations existing between the layers. A number of these layers makes primary particles with a height of about 8∼10nm and these primary particles make aggregates with a size of about 0.1∼10$\mu\textrm{m}$. When layered silicate was made to be organophilic, by exchanging the interlayer cations with organic cationic molecules, the matrix polymer can penetrate between the layers to give a nanocomposite, where 1nm-scal clay layers exist separately in a continuous polymer matrix. These nanostructured hybrid organic-inorganic composites have attracted the great interest of researchers over the last 10 years. They exhibit improved performance properties compared with conventional composites, because their unique phase morphology by layer intercalation or exfoliation maximizes interfacial contact between the organic and inorganic phases and enhances interfacial properties. Since the advent of nylon-6/montmorillonite nanocomposite developed by Toyota Motor Co., the studies on layered silicate-polymer nanocomposites have been successfully extended to other polymer systems. They greatly improved the thermal, mechanical, barrier, and even the flame-retardant properties of the polymers.

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The Effect of Sb2O3 Additive on the Electrical Properties of ZnO Varistor (Sb2O3 첨가제가 ZnO 배리스터의 전기적 특성에 미치는 영향)

  • Kim, Yong-Hyuk
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.65 no.10
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    • pp.1697-1701
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    • 2016
  • The leakage conduction and critical voltage characteristic of ZnO ceramic were investigated as a function of $Sb_2O_3$ concentration. Leakage conduction in the ohmic region increased with increasing $Sb_2O_3$ concentration and was attributed to the potential barrier height. The nonlinear coefficient increased with an increasing amount of $Sb_2O_3$. It was found that increases in the apparent critical voltages were associated with the lowered donor concentration in the grain boundary of between two ZnO grains. And the decrease of donor concentration on doping with $Sb_2O_3$ additive was attributed to the lowered capacitance in the grain boundary layer.

Metal-Oxide-Semiconductor Photoelectric Devices (Metal-Oxide-Semiconductor 광전소자)

  • Kang, Kilmo;Yun, Ju-Hyung;Park, Yun Chang;Kim, Joondong
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.27 no.5
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    • pp.276-281
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    • 2014
  • A high-responsive Schottky device has been achieved by forming a thin metal deposition on a Si substrate. Two-different metals of Ni and Ag were used as a Schottky metal contact with a thickness about 10 nm. The barrier height formation between metal and Si determines the rectifying current profiles. Ag-embedding Schottky device gave an extremely high response of 17,881 at a wavelength of 900 nm. An efficient design of Schottky device may applied for photoelectric devices, including photodetectors and solar cells.

On the Characteristics of Oxide Film on Gap (GaP 산화막 특성에 관하여)

  • Park, J.W.;Moon, D.C.;Kim, S.T.
    • Proceedings of the KIEE Conference
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    • 1988.11a
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    • pp.193-195
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    • 1988
  • The native oxide films were thermally and anodically formed on the n-GaP substrates grown by SSD method and measured this oxide thickness and the chemical composition and the electrical properties with formation condition. The chemical composition of themally oxidized GaP film was composed of mostly $GaPO_4$ at temperature below $800^{\circ}C$ and mostly $\beta-Ga_{2}O_{3}$ above $800^{\circ}C$. But The chemical composition of anodically oxidized GaPfilm was composed of the mixture of $Ga_{2}O_{3}$ and $P_{2}O_{5}$. The barrier height of Al/oxide/n-Gap which was formed at $700^{\circ}C$ by thermal oxidation method were 1.10eV, 1.03eV in Current-Voltage measurement. Interface charge density were $4{\times}10^{12}q(C/cm^2)$ and $3{\times}10^{12}q(C/cm^2)$ in Capacitance-Voltage measurement respectively.

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RTA Dependence of Pd/Ge/Pd/Ti/Au-InGaAs Ohmic Contact (Pd/Ge/Pd/Ti/Au-InGaAs 오믹접촉의 급속 열처리 의존성)

  • 박성호;김좌연;김일호
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1998.11a
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    • pp.151-154
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    • 1998
  • We have investigated a correlation of the electrical properties of the Pd/Ge/Pd/Ti/Au ohmic contact on n-InGaAs with its microstructures for the high temperature application of compound semiconductor devices. The samples were heat-treated by the rapid thermal annealing at various temperatures. In the contact system, moderately good specific contact resistance was obtained even before annealing because of the low metals-InGaAs barrier height, and better ohmic performances were observed by annealing up to 400˚C. But the ohmic performance was degraded after annealing at 450˚C due to the increment of Pd$_2$Ga$\sub$5/ phases.

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Dielectric and Electrical Characteristics of Fatty Acid LB films (지방산계 LB막의 유전 및 전기적 특성)

  • Choi, Yong-Sung;Kim, Do-Kyun;Chang, Jeong-Soo;Kwon, Young-Soo
    • Proceedings of the KIEE Conference
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    • 1998.11c
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    • pp.819-821
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    • 1998
  • Arachidic acid(AA) was used as LB films and its dielectric and conduction characteristics were investigated. The relative dielectric constant(${\varepsilon}_{LB}$) of AA LB films obtained from capacitance-frequency properties was about $3.5{\sim}4.1$. And the conductivity(${\sigma}_{LB}$) of AA LB films obtained from Current-Voltage characteristics was about $2.6{\times}10^{-15}[S/cm]$. Also, the conduction mechanism of current in LB films was dependant on Schottky type and the barrier height obtained from Schottky plot was about 1.4[eV].

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Fabrication of Three-Dimensional Reflective White Pattern using Dry-Film Resist

  • Jun, Hwa Joon;Na, Dae Gil;Kwon, Young Hoon;Kwon, Jin Hyuk
    • Journal of the Optical Society of Korea
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    • v.19 no.1
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    • pp.80-83
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    • 2015
  • White reflective patterns are very difficult to fabricate, due to the scattering and reflection of light, especially when the pattern size goes down to micron size. A reflective white barrier structure of height $50{\mu}m$ and width $80{\mu}m$ was fabricated using dry-film resist as an intermediate reverse pattern. The reverse dry-film resist pattern was coated with an $SiO_2$ layer by sputtering, to protect the resist from chemical attack by the radical molecules in UV white resin. The UV white resin was applied on the dry-film resist pattern and then cured with ultraviolet light. The fine three-dimensional reflective patterns were finished by removing the dry-film resist.

Effect of $HfO_X$ treatment on ITO surface of organic light emitting diodes using Impedance spectroscopy analysis

  • Cho, Jae-Hyun;Park, Hyung-Jun;Han, Kyu-Min;Sohn, Sun-Young;Jung, Dong-Geun;Yi, Jun-Sin
    • 한국정보디스플레이학회:학술대회논문집
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    • 2008.10a
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    • pp.506-508
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    • 2008
  • In this work, we used impedance spectroscopy analysis to determine the effect of the $HfO_X$ treatment on the surface of ITO and to model the equivalent circuit for OLEDs. Devices with an ITO/Organic material/Al structure can be modeled as resistances and capacitances arranged in parallel or in series. The number of elements depends on the composition of the structure, essentially the number of layers, and the contacts.

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