• 반도체디스플레이기술학회지
• /
• 제17권3호
• /
• pp.27-30
• /
• 2018

In this study, ZnO film was deposited on polycarbonate substrate by spin-spray method at low substrate temperature of $85^{\circ}C$. Surface morphology of ZnO films was changed by adding citrate from rod to dense structure. As-deposited ZnO film indicated high transmittance above 80%. In case of the resistivity, as-deposited ZnO film had high resistivity due to the existence of organic substance in the film. However, organic substance was removed and resistivity was decreased to $3.9{\times}10^{-2}{\Omega}{\cdot}cm$, after UV irradiation.

• 대한기계학회:학술대회논문집
• /
• 대한기계학회 2007년도 춘계학술대회B
• /
• pp.2182-2187
• /
• 2007

The relative contributions of phonon and electron to the thermal conductivity of silicon film with varying doping density are evaluated from the modified electron-phonon interaction model, which is applicable to the micro/nanoscale simulation of energy transport between energy carriers. The thermal conductivities of intrinsic silicon layer thicknesses from 20 nm to 500 nm are calculated and extended to the variation in n-type doping densities from 1.0 ${\times}$ $10^{18}$ to 5.0 ${\times}$ $10^{20}$ $cm^{-3}$, which agree well with the experimental data and theoretical model. From simulation results, the phonon and electron contributions to thermal conductivity are extracted. The electron contribution in the silicon is found to be not negligible above $10^{19}$ $cm^{-3}$, which can be classified as semimetal or metal by the value of its electrical resistivity at room temperature. The thermal conductivity due to electron is about 57.2% of the total thermal conductivity at doping concentration 5.0 ${\times}$ $10^{20}$ $cm^{-3}$ and silicon film thickness 100 nm.

• 지구물리와물리탐사
• /
• 제22권2호
• /
• pp.62-71
• /
• 2019

이 연구에서는 전기비저항 탐사와 자기지전류(magnetotellurics, MT) 탐사를 이용하여 미얀마 중앙분지에 대한 탐사를 수행하였다. 미얀마에서는 지하구조의 전기비저항 구조로 해석한 연구가 미흡하여 심부까지 전기비저항을 제공해 주는 대표적인 탐사를 활용하여 지하구조를 분석하였다. 연구지역 지질은 셰일층과 사암층으로 구성된 해성퇴적층으로 지하의 전기비저항 값이 낮을 것으로 예상되었다. 이 연구는 (주)지오룩스에서 자체 개발한 전기비저항 탐사 장비(SmartRho)와 Phoenix사의 MTU-5A를 사용하여 연구지역에 대한 전기비저항 구조를 영상화하였다. 전기비저항 탐사와 MT 탐사는 지하 100 m까지는 수십ohm-m 미만의 전기비저항 구조를 보였다. 특히 MT 탐사 자료에서는 1 Hz 까지 TM, TE 모드가 거의 유사한 양상을 보인다. MT 탐사 2차원 역산 결과 150 ohm-m 이하의 낮은 전기비저항 구조를 나타냈고, 동서방향으로 전기비저항 구조가 나뉘는 것을 확인할 수 있었다. MT 탐사를 전기비저항 탐사와 인접한 위치에서 수행한 결과, 2차원 역산 결과가 유사한 전기비저항 값을 나타내는 것을 확인하였다. 향후 미얀마 중앙분지의 전기비저항 구조 연구를 위해서는 높은 전기전도도를 고려하여 전기비저항 탐사와 MT 탐사를 동시 수행하는 것이 효과적일 것으로 생각된다.

• Journal of Mechanical Science and Technology
• /
• 제15권5호
• /
• pp.630-638
• /
• 2001

The electrical resistivity of sinter dusts generated from the steel industry and coal fly ash from the coal power plant has been investigated using the high voltage conductivity cell based on JIS B 9915 as a function of temperature and water content. Dust characterization such as the chemical composition, size distribution, atomic concentration, and surface structure has been conducted. Major constituents of sinter dusts were Fe$_2$O$_3$(40∼74.5%), CaO (6.4∼8.2%), SiO$_2$(4.1∼6.0%), and unburned carbon (7.0∼14.7%), while the coal fly ash consisted of mainly SiO$_2$(51.4%), Al$_2$O$_3$(24.1%), and Fe$_2$O$_3$(10.5%). Size distributions of the sinter dusts were bi-modal in shape and the mass median diameters (MMD) were in the range of 24.7∼137㎛, whereas the coal fly ash also displayed bi-modal distribution and the MMD of the coal fly ash was 35.71㎛. Factors affecting resistivity of dusts were chemical composition, moisture content, particle size, gas temperature, and surface structure of dust. The resistivity of sinter dusts was so high as 10(sup)15 ohm$.$cm at 150$\^{C}$ that sinter dust would not precipitate well. The resistivity of the coal fly ash was measured 1012 ohm$.$cm at about 150$\^{C}$. Increased water contents of the ambient air lowered the dust resistivity because current conduction was more activated for absorption of water vapor on the surface layer of the dust.

• 대한설비공학회:학술대회논문집
• /
• 대한설비공학회 2009년도 하계학술발표대회 논문집
• /
• pp.183-188
• /
• 2009

RFID method is a non-contact automatic identification technology, which attaches microchips and antennas to an object in a tag form, to send and process information sent to the network using wireless frequency. Drying and curing process is extremely important which minimizes the resistivity of RFID antennas. This research is about the drying characteristic of conductivity ink, and analyzes and compares the hot-air drying process and infrared drying process. Also, the research was done for the improvement in drying performance by using combined process of hot-air and infrared mechanism. The experiment result shows that the hot-air or infrared drying system used alone cannot meet the required performance in drying printing method using conductivity ink. The combined drying system of hot-air and infrared ray showed resistance low enough in short drying and curing time, and this mechanism makes drying and curing process for mass and continuous production possible on-line.

• Composites Research
• /
• 제17권5호
• /
• pp.61-67
• /
• 2004

본 연구에서는 전자파 차폐용 도전성 개스킷 소재로 활용할 수 있는 은입자 충전 실리콘 복합 페이스트에 대한 전기전도성 및 응력-변형율 특성을 분석하였다. 불규칙한 구형의 은(Ag)입자와 상온습기경화형(RTV) 실리콘수지를 도입하여 복합 페이스트의 퍼콜레이션 농도(임계 농도)를 전기전도도 측정 결과로부터 결정하였다. 약 28%의 은입자 함량에서 퍼콜레이션 현상이 발생하였으며, 이 농도에서 급격한 감소를 보이는 은입자/실리콘 복합 페이스트의 체적 비저항, 인장강도 및 연신률의 특성 변화에 관하여 고찰하였다. 또한, 커플링제의 선택적 방법을 통해 퍼콜레이션 농도 이상으로 충전된 복합 페이스트의 응력-변형율 특성을 효과적으로 개선할 수 있음을 제시하여 주었다.

• 한국전기전자재료학회논문지
• /
• 제18권5호
• /
• pp.407-413
• /
• 2005

Ion implantation provides a unique way to modify the mechanical, optical and electrical properties of polymer by depositing the energy of ions in the material on the atomic scale. Implantation of ions into the polymers generally leads to a radiation damage, which, in many cases, modifies the properties of the surface and bulk of the material. These modifications result from the changes of the chemical structure caused in their turn by changing the chemical bonding when the incident ions cut the polymer chains, breaks covalent bonds, promotes cross-linking, and liberates certain volatile species. We studied the relation among the linear energy transfer (LET) and changes of surface microstructure and surface resistivity on PPS material using the high current ion implantation technology The surface resistivity of nitrogen implanted PPS decreased to $10^{7}{\Omega}/cm^{2}$ due to the chain scission, cross linking, ${\pi}$ electron creation and mobility increase. In this case, the surface conductivity depend on the 1-dimensional hopping mechanism.

• 센서학회지
• /
• 제1권2호
• /
• pp.165-172
• /
• 1992

3가와 5가 이온의 첨가가 전기전도도 및 감응도에 어떤 영향을 미치는가를 확인하기 위하여, In와 Sb를 Tin Oxide에 공침법으로 첨가하였다. Sb는 5가 이온으로 cassiterite 구조에 들어가서 열에너지에 의하여 이들 이온을 여기시켜 전도대로 밀어올리리라고 여겨진다. In 이온은 결정격자 속에 $In^{3+}$로 들어가서 원자가대로 부터 전자를 받게 되고 그러므로써 1가나 2가가 되리라 생각한다. 그러나, 이러한 현상들이 $SnO_{2}$에 존재하는 전위장벽을 2종의 이온첨가에 의하여 일어나는 resistivity에 끼치는 영향과 비교해 볼 때 감응도에는 어떤 영향을 보이는지 고찰하였다.

• 한국재료학회지
• /
• 제19권12호
• /
• pp.644-648
• /
• 2009

Temperature dependency of resistivity of the carbon black-polyethylene composites below and above percolation threshold is studied based on the electrical conduction mechanism. Temperature coefficient of resistance of the composites below percolation threshold changed from minus to plus, increasing volume fraction of carbon black; this trend decreased with increasing volume fraction of carbon black. The temperature dependence of resistivity of the composites below percolation threshold can be explained with a tunneling conduction model by incorporating the effect of thermal expansion of the composites into a tunneling gap. Temperature coefficient of resistance of the composites above percolation threshold was positive and its absolute value increased with increasing volume fraction of carbon black. By assuming that the electrical conduction through percolating paths is a thermally activated process and by incorporating the effect of thermal expansion into the volume fraction of carbon black, the temperature dependency of the resistivity above percolation threshold has been well explained without violating the universal law of conductivity. The apparent activation energy is estimated to be 0.14 eV.

• 한국재료학회지
• /
• 제31권2호
• /
• pp.108-114
• /
• 2021

In the manufacturing of bulk graphite, pores produced by vaporization and discharge of volatile materials in binders during carbonization reduce the density of bulk graphite, which adversely affects the electrical conductivity, strength and mechanical properties. Therefore, an impregnation process is introduced to fill the pores and increase the density of bulk graphite. In this study, bulk graphite is prepared by varying the viscosity of the impregnant. The microstructure of bulk graphite is observed. The flexural strength and electrical resistivity are measured. As the viscosity of the impregnants decreases and the number of impregnations increases, it is shown that the number of pores decreases. The density before impregnation is 1.62 g/㎤. The density increases to 1.67 g/㎤ and porosity decreases by 18.6 % after three impregnations using 5.1 cP impregnant, resulting in the best pore-filling effect. After three times of impregnation with a viscosity of 5.1 cP, the flexural strength increases by 55.2 % and the electrical resistivity decreases by 86.76 %. This shows that a slight increase in density due to the pore-filling effect improves the properties of bulk graphite.