LabVIEW 기반 피뢰기 I-V특성 분석장치

정기우(Gi-Woo Jeong),김선재(Sun-Jae Kim),길경석(Gyung-Suk Kil),박희철(Hee-Chul Park) 한국철도학회 2013 한국철도학회 학술발표대회논문집 Vol.2013 No.11

본 논문에서는 철도용 피뢰기의 관리를 위한 I-V 특성 분석장치에 대하여 기술하였다. 분석장치는 직류 고전압 발생장치, 데이터 수집모듈 및 제어부로 구성되며, LabVIEW 를 이용하여 데이터를 분석하도록 설계하였다. 분석 프로그램은 최대 전류와 시험 전압을 100 V/s 의 비율로 인가하도록 설정할 수 있다. DAQ 에서는 피뢰기의 누설전류와 인가 전압을 측정한다. 그 값으로부터 분석장치에 I-V 특성 곡선을 나타내고, 피뢰기의 상태 진단에 활용될 수 있다. In this paper, we described the I-V characteristic analyzer to diagnose lightning arrester for traction systems. The analyzer is composed of a DC high voltage power supply, a data acquisition module and a control unit, and is designed to analyze measured data using a LabVIEW program. An analysis program set the applied test voltage with the rate of 100 V/s and the maximum current. The DAQ detects leakage current flowing an arrester under test and applied voltage. From the value, the analyzer displays I-V characteristics curve, and we can identify the soundness of the arrester.

Intrinsic Cylindrical/Surrounding Gate SOI MOSFET의 I-V 특성 도출을 위한 해석적 모델

우상수,이재빈,서정하 대한전자공학회 2011 電子工學會論文誌-SD (Semiconductor and devices) Vol.48 No.10

In this paper, a simple analytical model for deriving the I-V characteristics of a cylindrical surrounding gate SOI MOSFET with intrinsic silicon core is suggested. The Poisson equation in the intrinsic silicon core and the Laplace equation in the gate oxide layer are solved analytically. The surface potentials at both source and drain ends are obtained by means of the bisection method. From them, the surface potential distribution is used to describe the I-V characteristics in a closed-form. Simulation results seem to show the dependencies of the I-V characteristics on the various device parameters and applied bias voltages within a range of satisfactory accuracy. 본 논문에서는 intrinsic-body cylindrical/surrounding gate SOI MOSFET의 I-V 특성 도출을 위한 간단한 해석적 모델을제시하였다. Intrinsic 실리콘 채널 영역에서의 Poisson 방정식과 gate oxide 내에서의 Laplace 방정식을 해석적으로 풀어 소스와 드레인 양단 끝에서의 표면 전위 분포를 bisection method를 이용하여 구하였다. 구해진 표면 전위를 바탕으로 closed-form 의 I-V 특성 식을 도출하였다. 도출된 I-V 특성 표현 식을 모의 실험한 결과, 소자의 parameter와 가해진 bias 전압에 대한비교적 정확한 의존성을 확인할 수 있었다.

Intrinsic Cylindrical/Surrounding Gate SOI MOSFET의 Ⅰ-V 특성 도출을 위한 해석적 모델

우상수(Sang-Su Woo),이재빈(Jae-Bin Lee),서정하(Chung-Ha Suh) 大韓電子工學會 2011 電子工學會論文誌-SD (Semiconductor and devices) Vol.48 No.10

본 논문에서는 intrinsic-body cylindrical/surrounding gate SOI MOSFET의 I-V 특성 도출을 위한 간단한 해석적 모델을 제시하였다. Intrinsic 실리콘 채널 영역에서의 Poisson 방정식과 gate oxide 내에서의 Laplace 방정식을 해석적으로 풀어 소스와 드레인 양단 끝에서의 표면 전위 분포를 bisection method를 이용하여 구하였다. 구해진 표면 전위를 바탕으로 closed-form의 I-V 특성 식을 도출하였다. 도출된 I-V 특성 표현식을 모의 실험한 결과 소자의 parameter와 가해진 bias 전압에 대한 비교적 정확한 의존성을 확인할 수 있었다. In this paper a simple analytical model for deriving the I-V characteristics of a cylindrical surrounding gate SOI MOSFET with intrinsic silicon core is suggested. The Poisson equation in the intrinsic silicon core and the Laplace equation in the gate oxide layer are solved analytically. The surface potentials at both source and drain ends are obtained by means of the bisection method. From them the surface potential distribution is used to describe the I-V characteristics in a closed-form. Simulation results seem to show the dependencies of the I-V characteristics on the various device parameters and applied bias voltages within a range of satisfactory accuracy.

Fabrication and structural, electrical characterization of i-ZnO/n-ZnO nanorod homojunctions

S. Yılmaz,E. Bacaksız,İ. Polat,Y. Atasoy 한국물리학회 2012 Current Applied Physics Vol.12 No.5

Well-aligned ZnO nanorods were synthesized by a vapor phase transport method on ZnO buffer layer coated n-Si substrates. X-ray diffraction and scanning electron microscopy results showed that the deposited ZnO nanorods crystallize in the wurtzite structure and are highly textured with their c-axes normal to the substrate and show a clearly hexagonal morphology. A heavily compensated and intrinsic ZnO layer (i-ZnO) doped with both Mg and Na was deposited on the nominally undoped ZnO nanorods (which show a natural n-type behavior) to produce an i-ZnO/n-ZnO homojunction. The i-ZnO layer consisted of the grainy shape nano-crystallites with the wavy surface morphology. The currentevoltage (I-V) characteristics of these structures in the temperature range of 150e300 K have been analyzed in the framework of standard thermionic emission (TE) theory with the assumption of a Gaussian distribution of the barrier heights. The values of zero bias barrier height (Φb0) and ideality factor (n) were found to be strongly temperature dependent whereby n decreases while Φb0 increases with increasing temperature. The ln(I0/T2) vs q/kT plot shows a straight line behavior and the values of activation energy (Ea = Φb0) and the Richardson constant (A*) determined from the intercept and slope of the plot were 0.926 eV and 2.61 × 10-8 A cm-2 K-2, respectively. This value of A* is much lower than the known value of 32 A cm-2 K-2 for ZnO. Thus, a modified ln(0=T2)-(σ20q2=2k2T2)vs. q/kT plot based on a Gaussian distribution of barrier heights was used which yields a mean barrier height (Φb)and modified effective Richardson (A**) of 1.032 eV and 34.85 A cm- K-, respectively. This value of A** is much closer to the theoretical value of 32 A cm-2K-2 for ZnO.

직접 메탄올 연료전지용 메탄올 센서의 백금 두께의 변화에 따른 전류-전압 특성 변화

양진석,김성일,김춘근,박정호,Yang, Jin-Seok,Kim, Seong-Il,Kim, Chun-Keun,Park, Jung-Ho 한국마이크로전자및패키징학회 2007 마이크로전자 및 패키징학회지 Vol.14 No.1

직접 메탄올 연료전지는 간단한 구조와 디자인 그리고 높은 에너지 밀도와 에너지 변환 효율등의 장점으로 인하여 휴대용 장치들의 전력원으로 사용된다. 본 논문에서는 직접 메탄올 연료전지의 연료 농도를 감지하기 위한 얇은 나피온 막과 Pt 촉매전극의 합성으로 만들어진 메탄을 센서를 제작하였다. 제작된 메탄을 센서를 사용하여 메탄올 농도와 촉매전극(Pt)의 두께 변화에 따른 전류-전압 특성을 분석하였다. Pt 촉매전극 10nm, 전압이 1V 이고 메탄올 농도 1, 2, 3M일 때 전류 값이 각각 $1.30{\times}10^{-6}A,\;1.96{\times}10^{-6}A,\;2.80{\times}10^{-6} A$ 이었다. 메탄올 농도를 2M로 고정하고 촉매전극의 두께를 5, 10, 15nm로 변화시켰을 때 전류 값은 각각 $3.06{\times}10^{-6}A,\;1.96{\times}10^{-6}A,\;1.00{\times}10^{-6}A$ 이었다. 촉매전극이 얇을수록 전류가 증가하고 전기화학반응이 더 활발히 일어나는 것으로 사료된다. The direct methanol fuel cell (DMFC) is a promising power source for portable applications due to many advantages such as simple construction, compact design, high energy density, and relatively high energy-conversion efficiency. In this work, an electrochemical methanol sensor for monitoring the methanol concentration in direct methanol fuel cells was fabricated using a thin composite nafion membrane as the electrolyte. We have analyzed the I-V characteristic of the fabricated methanol sensor as a function of methanol concentration, catalyst electrode and platinum(Pt) thickness. The fabricated sensor was analyzed by I-V measurement with various methanol concentration. When we measured the sensor characteristics with 10nm Pt and at 1V, the current value was $1.30{\times}10^{-6}A,\;1.96{\times}10^{-6}A\;and\;2.80{\times}10^{-6} A$ for three methanol concentration of 1M, 2M and 3M, respectively. When the methanol concentration was fixed at 2M, the current value of the fabricated device with Pt layers of 5, 10 and 15 nm thickness was $3.06{\times}10^{-6}A,\;1.96{\times}10^{-6}A\;and\;1.00{\times}10^{-6}A$, respectively. These results lead us to the conclusion that when the methanol concentration increases, the output current increases and when the catalyst electrode become thinner, the current increase more. It showed that, the thinner the catalyst electrode, the more electrochemistry become activation.

Investigation on I-V characteristics of current induced metal insulator transition in VO2 device

이기용,김호원,문봉진,박창우,주홍렬 한국물리학회 2017 Current Applied Physics Vol.17 No.11

The I-V characteristics of two terminal planar VO2 film devices are investigated as the devices undergo the current induced metal insulator transition (I-MIT). The I-MIT occured when the device resistivity reached ~7 Ucm, where metallic grains formed initial conductive current path within insulating matrix. The transition time needed for the I-MIT increased with increasing external resistance, REXT, connected to the device in series, i.e. ~390 ms (REXT ¼ 5 kU) to ~1400 ms (REXT ¼ 20 kU). The transition time is closely related to the RC time delay from capacitance discharge of the VO2 device. During the I-MIT, the amount of discharge current was estimated as large as ~100 mA, which was larger than the current just before the I-MIT. After the I-MIT, the current density decreased from 1.1 『 106 A/cm2 to 6.5 『 105 A/cm2, suggesting a large temperature changes up to ~300 』C.

p-Si 기판에 n-형으로 도핑되어 증착된 TiO2 박막의 전류-전압 특성

정우일,맹진영,송종현 한국물리학회 2023 새물리 Vol.73 No.4

We fabricated p-n junction devices by depositing Nb-doped TiO2 thin films on p-Si (100) substrates using pulsed laser deposition method with Nb-doping rates of 0%, 3%, and 6% and carried out current–voltage (I-V) measurements to characterize their electrical transport properties. Results revealed that the undoped TiO2/p-Si device exhibited the ideal diode characteristics when the ideality factor, zero bias barrier height extracted by applying thermionic emission theory, T0 anomaly, and distribution of the zero bias barrier height versus the ideality factor were considered. Rectification characteristics were observed even in device without Nb doping. This phenomenon is interpreted as the natural n-type doping effect of TiO2 thin film due to oxygen deficiencies. For the Nb:TiO2/p-Si device with Nb doping, the inhomogeneities in barrier height increased compared with that of the undoped device. As a result, the characteristics of the diode device degraded. These observations provide insights into the optimal doping condition for the device applications of TiO2. 이 연구에서는 TiO2에 Nb이 각각 0%, 3%, 6%의 도핑율로 도핑된 박막을 펄스 레이저 증착(Pulsed Laser Deposition, PLD) 방법으로 p-Si (100) 기판 위에 증착하여 p-n 접합 소자를 제작하였으며 이들 소자에 대하여 전류-전압(I-V) 특성 분석을 수행하였다. I-V 곡선에 열전자 방출(Thermionic emission) 이론을 적용하여 추출한 이상 계수(Ideality factor)와 제로 바이어스 장벽 높이(Zero bias barrier height), 그리고 T0 변칙과 이상 계수 대비 제로 바이어스 장벽 높이의 분포 분석에 따르면 도핑과정을 거치지 않은 TiO2/p-Si 소자가 이상적인 다이오드 특성과 가장 가까운 것으로 나타났다. Nb 도핑과정이 이루어지지 않은 소자의 경우에서도 정류특성이 관측되는 것은 산소 결핍에 의한 TiO2 박막내에서의 n-형 도핑 효과로 해석된다. Nb 도핑을 한 Nb:TiO2/p-Si 소자의 경우 도핑과정을 거치지 않은 산소 결핍 도핑 소자보다 장벽높이의 불균질성이 증가하여 오히려 다이오드 소자 특성이 우수하지 않은 것으로 나타났다. 이와 같은 결과는 TiO2의 소자 응용측면에서 최적의 도핑조건에 대한 실마리를 제공한다고 할 수 있다.

Investigation on I-V characteristics of current induced metal insulator transition in VO₂ device

Lee, G.Y.,Kim, H.,Mun, B.S.,Park, C.,Ju, H. Elsevier 2017 Current Applied Physics Vol.17 No.11

<P>The I-V characteristics of two terminal planar VO2 film devices are investigated as the devices undergo the current induced metal insulator transition ( I-MIT). The I-MIT occured when the device resistivity reached similar to 7 Omega cm, where metallic grains formed initial conductive current path within insulating matrix. The transition time needed for the I-MIT increased with increasing external resistance, R-EXT, connected to the device in series, i.e. similar to 390 mu s (R-EXT = 5 k Omega) to similar to 1400 ms (R-EXT = 20 k Omega). The transition time is closely related to the RC time delay from capacitance discharge of the VO2 device. During the I-MIT, the amount of discharge current was estimated as large as similar to 100 mA, which was larger than the current just before the I-MIT. After the I-MIT, the current density decreased from 1.1 x 10(6) A/cm(2) to 6.5 x 10(5) A/cm(2), suggesting a large temperature changes up to similar to 300 degrees C. (C) 2017 Elsevier B.V. All rights reserved.</P>

Fabrication and electrical characterization of p-Sb_2S_3/n-Si heterojunctions for solar cells application

K.F. Abd-El-Rahman,A.A.A. Darwish 한국물리학회 2011 Current Applied Physics Vol.11 No.6

Antimony trisulphide (Sb_2S_3) films were prepared by thermal evaporation technique on n-type single crystal Si substrates to fabricate p-Sb_2S_3/n-Si heterojunctions. The electrical transport properties of the peSb_2S_3/n-Si heterojunctions were investigated by currentevoltage (I―V) and capacitance―voltage (C―V) measurements. The temperature-dependent I―V characteristics revealed that the forward conduction was determined by multi-step tunnelling current and the activation energy of saturation current was about 0.54 eV. The 1/C^2―V plots indicated the junction was abrupt and the junction built-in potential was 0.6 V at room temperature and decreased with increasing temperature. The solar cell parameters have been calculated for the fabricated cell as V_oc = 0.50 V, J_sc = 14.53 mA cm^-2, FF = 0.32 and η = 4.65% under an illumination of 50 mW cm^-2.

Estimation of Electrical Parameters of OD Organic Semiconductor Diode from Measured I-V Characteristics

Syed Abdul Moiz,Mansoor M. Ahmed,Kh. S. Karimov 한국전자통신연구원 2005 ETRI Journal Vol.27 No.3

In this paper the effect of temperature on the electrical properties of organic semiconductor disperse orange dye 25 (OD) have been examined. Thin films of OD have been deposited on In2O3 substrates using a centrifugal machine. DC current-voltage (I-V) characteristics of the fabricated devices (Al/OD/In2O3) have been evaluated at varying temperatures ranging from 40 to 60°C. A rectification behavior in these devices has been observed such that the rectifying ratio increases as a function of temperature. I-V characteristics observed in Al/OD/In2O3 devices have been classified as low temperature (≤ 50°C) and high temperature characteristics (approximately 60°C). Low temperature characteristics have been explained on the basis of the charge transport mechanism associated with free carriers available in OD, whereas high temperature characteristics have been explained on the basis of the trapped space-charge-limited current. Different electrical parameters such as traps factor, free carrier density, trapped carrier density, trap density of states, and effective mobility have been determined from the observed temperature dependent I-V characteristics. It has been shown that the traps factor, effective mobility, and free carrier density increase with increasing values of temperature, whilst no significant change has been observed in the trap density of states.