• Title/Summary/Keyword: Leakage Current-Voltage Curve

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Electrical Leakage Levels Estimated from Luminescence and Photovoltaic Properties under Photoexcitation for GaN-based Light-emitting Diodes

  • Kim, Jongseok;Kim, HyungTae;Kim, Seungtaek;Choi, Won-Jin;Jung, Hyundon
    • Current Optics and Photonics
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    • v.3 no.6
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    • pp.516-521
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    • 2019
  • The electrical leakage levels of GaN-based light-emitting diodes (LEDs) containing leakage paths are estimated using photoluminescence (PL) and photovoltaic properties under photoexcitation conditions. The PL intensity and open-circuit voltage (VOC) decrease because of carrier leakages depending on photoexcitation conditions when compared with reference values for typical LED chips without leakage paths. Changes of photovoltage-photocurrent characteristics and PL intensity due to carrier leakage are employed to assess the leakage current levels of LEDs with leakage paths. The current corresponding to the reduced VOC of an LED with leakage from the photovoltaic curve of a reference LED without leakage is matched with the leakage current calculated using the PL intensity reduction ratio and short-circuit current of the LED with leakage. The current needed to increase the voltage for an LED with a leakage under photoexcitation from VOC of the LED up to VOC of a reference LED without a leakage is identical to the additional current needed for optical turn-on of the LED with a leakage. The leakage current level estimated using the PL and photovoltaic properties under photoexcitation is consistent with the leakage level measured from the voltage-current characteristic obtained under current injection conditions.

A Study on the DC Leakage Current Test for Power Cable of Private Electrical Facilities considering Lightning Arrester (피뢰기를 고려한 자가용 전기설비 인입선로의 직류누설전류시험에 관한 연구)

  • Jeong, Ki-Seok;Gil, Hyoung-Jun
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.67 no.1
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    • pp.142-147
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    • 2018
  • Private electrical facilities are judged whether it is suitable for the insulation aging condition of their incoming underground cables using DC leakage current test method. In the case where the service point of utility is the secondary side of cut out switch installed in the electric pole, there is a problem that it is difficult to separate the lightning arresters(LA) because of their high position of the pole. Therefore, the field test voltage is applied at value lower than DC 30 kV, which are stated in the inspection guideline. However, this test could reduced the insulation performance of the LA by accelerating the electrical stress of the metal oxide varistor element in the pre-breakdown region. In this study, we analyzed the relationship between the DC test voltage and the leakage current using the non-destructive DC high voltage equipment with leakage current measurement function. The results show that the leakage current increases sharply above the specified test voltage. As a consequence, it could be contributed to improve insulation aging inspection method by selecting the possible test area on the VI characteristic curve of the pre-breakdown area of the LA.

Deterioration Characteristics of ZnO Surge Arrester Blocks for Power Distribution Systems Due to Impulse Currents (임펄스전류에 의한 배전용 ZnO 피뢰기 소자의 열화특성)

  • Lee, Bok-Hee;Cho, Sung-Chul;Yang, Soon-Man
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.27 no.3
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    • pp.79-86
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    • 2013
  • In order to analyze the electrical performance of ZnO surge arresters stressed by the combined DC and AC voltages that are generated in DC/AC converter systems, the leakage current properties of ZnO surge arrester blocks deteriorated by impulse currents were investigated. The test specimens were deteriorated by the 8/$20{\mu}s$ impulse current of 2.5kA and the leakage currents flowing into the deteriorated zinc oxide(ZnO) arrester blocks subjected to the combined DC and power frequency AC voltages are measured. As a result, the leakage currents flowing through deteriorated ZnO surge arrester blocks were higher than those flowing through the fine ZnO surge arrester blocks and the larger the injection number of 8/$20{\mu}s$ impulse current of 2.5kA is, the greater the leakage current is. The leakage current-voltage curves(I-V curves) of the fine and deteriorated ZnO surge arrester blocks stressed by the combined DC and AC voltages show significant difference in the low conduction region. Also the cross-over phenomenon is observed at the voltage close to the knee of conduction on plots of I-V curves.

The Study on the Characteristics of Leakage Circuit Breakers in Protection of the Low Voltage Electrical Apparatus (저압전기기기의 보호를 위한 전류동작형 누전차단기의 특성에 관한 연구)

  • 김은배;오철수
    • 전기의세계
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    • v.25 no.4
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    • pp.59-62
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    • 1976
  • This study on the characteristics of the leakage circuit breakers handles the rolls of each itemized parts of the mentioned apparatus and their influence in determining of the characteristic curve of leakage circuit breaker. Furthermore the differential current transforms in the mentioned apparatus for detecting the fault is handled as a heavy point.

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Measurement and Analysis of Temperature Dependence for Current-Voltage Characteristics of Homogeneous Emitter and Selective Emitter Crystalline Silicon Solar Cells (Homogeneous 에미터와 Selective 에미터 결정질 실리콘 태양전지의 온도에 따른 전류-전압 특성 변화 측정 및 분석)

  • Nam, Yoon Chung;Park, Hyomin;Lee, Ji Eun;Kim, Soo Min;Kim, Young Do;Park, Sungeun;Kang, Yoonmook;Lee, Hae-Seok;Kim, Donghwan
    • Korean Journal of Materials Research
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    • v.24 no.7
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    • pp.375-380
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    • 2014
  • Solar cells exhibit different power outputs in different climates. In this study, the temperature dependence of open-circuit voltage(V-oc), short-circuit current(I-sc), fill factor(FF) and the efficiency of screen-printed single-crystal silicon solar cells were studied. One group was fabricated with homogeneously-doped emitters and another group was fabricated with selectively-doped emitters. While varying the temperature (25, 40, 60 and $80^{\circ}C$), the current-voltage characteristics of the cells were measured and the leakage currents extracted from the current-voltage curve. As the temperature increased, both the homogeneously-doped and selectively-doped emitters showed a slight increase in I-sc and a rapid degradation of V-oc. The FF and efficiency also decreased as temperature increased in both groups. The temperature coefficient for each factor was calculated. From the current-voltage curve, we found that the main cause of V-oc degradation was an increase in the intrinsic carrier concentration. The temperature coefficients of the two groups were compared, leading to the idea that structural effects could also affect the temperature dependence of current-voltage characteristics.

The characteristic of leakage current in ZnO surge arrestor elements with mixed direct and 60Hz voltage (중첩전압(직류+교류 60Hz)에서 산화아연 피뢰기 소자의 누설전류 특성)

  • Lee, B.H.;Pak, K.Y.;Kang, S.M.;Choi, H.S.;Oh, S.K.
    • Proceedings of the KIEE Conference
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    • 2003.10a
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    • pp.186-188
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    • 2003
  • The ZnO surge arrester is the protective device for limiting surge voltages on equipment by diverting surge current and returning the device to its original status. The occurrence of overvoltage appears in any phase to AC power supply system and it appears in mixing AC and impulse voltages, moreover because HVDC power supply system uses converter in semiconductor, it makes mixed DC and high harmonics voltages. In this study, the various mixed AC and DC voltages was made for investigating the degradation effect of ZnO arrester according to mixed voltage. As a result, the increase of DC component to mixed voltages causes the increase of resistive component of total leakage current to ZnO block. In changing V-I curve for mixed voltages, the cross-over point acts a factor as making the proper capacitor size of an equivalent circuit for ZnO block.

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Changes in Electrical Properties of ZnO Surge Arresters According to Surrounding Conditions (외부 환경조건에 따른 ZnO 피뢰기의 전기적 특성의 변화)

  • Lee, Seung-Ju;Lee, Su-Bong;Lee, Bok-Hee
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.22 no.9
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    • pp.62-68
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    • 2008
  • This paper describes the electrical characteristics of ZnO surge arresters associated with the variation of surrounding conditions. To investigate the deterioration behaviors of ZnO surge arresters due to lightning surges, 8/20[${\mu}s$], 2.5[kA] impulse currents were injected to the ZnO surge arrester under test. The leakage currents of ZnO surge arrester subject to power frequency AC voltage were measured in different surrounding temperature and wet conditions. As a result, it was found that the leakage current is increased and its asymmetry is pronounced as the number of injection of the impulse current and the ambient temperature increase. Also, in the wet test the outside leakage current flowing through the housing surface of the ZnO surge arrester is much larger than the intrinsic leakage current of ZnO surge arrester element. The results obtained in this work can be a lied as factors of improving the reliability and performance of monitoring system for surge arresters.

Fabrication of Electrostatic Chucks Using Borosilicate Glass Coating as an Insulating Layer (붕규산염 유리를 절연층으로 도포한 정전척의 제조)

  • Bang, Jae-Cheol;Lee, Ji-Hyung
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2001.11b
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    • pp.390-393
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    • 2001
  • This study demonstrated the feasibility of tape casting method to fabricate soda borosilicate glass-coated stainless steel electrostatic chucks(ESC) for low temperature semiconductor processes. The glass coatings on the stainless steel substrates ranged from $100{\mu}m$ to $150{\mu}m$ thick. The adhesion of the glass coatings was found to be excellent such that it was able to withstand moderate impact tests and temperature cycling to over $300^{\circ}C$ without cracking and delamination. The electrostatic clamping pressure generally followed the theoretical voltage-squared curve except at elevated temperatures and higher applied voltages when deviations were observed to occur. The deviation is due to increased leakage current at higher temperature and applied voltage as the electrical resistivity drops.

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Fabrication of Electrostatic Chucks Using Borosilicate Glass Coating as an Insulating Layer (붕규산염 유리를 절연층으로 도포한 정전척의 제조)

  • 방재철;이지형
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2001.11a
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    • pp.390-393
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    • 2001
  • This study demonstrated the feasibility of tape casting method to fabricate soda borosilicate glass-coated stainless steel electrostatic chucks(ESC) for low temperature semiconductor processes. The glass coatings on the stainless steel substrates ranged from 100 $\mu\textrm{m}$ to 150 $\mu\textrm{m}$ thick. The adhesion of the glass coatings was found to be excellent such that it was able to withstand moderate impact tests and temperature cycling to over 300$^{\circ}C$ without cracking and delamination. The electrostatic clamping pressure generally followed the theoretical voltage-squared curve except at elevated temperatures and higher applied voltages when deviations were observed to occur. The deviation is due to increased leakage current at higher temperature and applied voltage as the electrical resistivity drops.

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Device Characteristics of AlGaN/GaN MIS-HFET using $Al_2O_3$ Based High-k Dielectric

  • Park, Ki-Yeol;Cho, Hyun-Ick;Lee, Eun-Jin;Hahm, Sung-Ho;Lee, Jung-Hee
    • JSTS:Journal of Semiconductor Technology and Science
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    • v.5 no.2
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    • pp.107-112
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    • 2005
  • We present an AlGaN/GaN metal-insulator-semiconductor-heterostructure field effect transistor (MIS-HFET) with an $Al_2O_3-HfO_2$ laminated high-k dielectric, deposited by plasma enhanced atomic layer deposition (PEALD). Based on capacitance-voltage measurements, the dielectric constant of the deposited $Al_2O_3-HfO_2$ laminated layer was estimated to be as high as 15. The fabricated MIS-HFET with a gate length of 102 m exhibited a maximum drain current of 500 mA/mm and maximum tr-ansconductance of 125 mS/mm. The gate leakage current was at least 4 orders of magnitude lower than that of the reference HFET. The pulsed current-voltage curve revealed that the $Al_2O_3-HfO_2$ laminated dielectric effectively passivated the surface of the device.