• 제목/요약/키워드: blocking device

검색결과 244건 처리시간 0.028초

수평형 파워 MOSFET에 있어서 트렌치 Isolation 적용에 의한 순방향 항복특성 개선을 위한 새로운 소자의 설계에 관한 연구 (The Study of Improving Forward Blocking Characteristics for Small Sized Lateral Trench Electrode Power MOSFET using Trench Isolation)

  • 김진호;김제윤;유장우;성만영;김기남
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2004년도 하계학술대회 논문집 Vol.5 No.1
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    • pp.9-12
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    • 2004
  • In this paper, a new small sized Lateral Trench Electrode Power MOS was proposed. This new structure, called LTEMOS(Lateral Trench Electrode Power MOS), was based on the conventional lateral power MOS. But the entire electrodes of LTEMOS were placed in trench oxide. The forward blocking voltage of the proposed LTEMOS was improved by 1.5 times with that of the conventional lateral power MOS. The forward blocking voltage of LTEMOS was about 240 V. At the same size, an improvement of the forward blocking voltage of about 1.5 times relative to the conventional MOS was observed by using ISE-TCAD which was used for analyzing device's electrical characteristics. Because all of the electrodes of the proposed device were formed in each trench oxide, the electric field was crowded to trench oxide and punch-through breakdown was occurred, lately.

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혼-타의 수평틈새가 캐비테이션에 미치는 영향에 관한 수치적 연구 (A Numerical Study on the Influence of the Horizontal Gap upon the Cavitation Behavior of a Horn Type Rudder)

  • 서대원;이승희;김효철;오정근
    • 대한조선학회논문집
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    • 제47권2호
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    • pp.113-121
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    • 2010
  • Recently, as container ships become larger and faster, rudder cavitations are more frequently observed near the gap between the horn and rudder plates of the ships to cause serious damages to the rudder surface of the ship. The authors already have suggested through a series of model experiments and numerical computations that employment of an appropriate blocking device for gap flow may retard the gap cavitation. For examples, a cam device installed near the outer edges of the vertical gap or a water-injection device combined with a pair of half-round bars installed inside the gap can considerably reduce the gap cavitation. However, it is also found that effective blocking of the flow through the vertical gap results in growth of the cavitation near the horizontal gap instead. In the present study, effectiveness of the simultaneous blocking of the flow through the horizontal and vertical gaps of a horn type rudder in minimizing the damage by gap cavitation is studied. Additional blocking disks are inserted inside the horizontal gaps on the top and bottom of the pintle block and numerical computations are carried out to confirm the combined effect of the blocking devices.

Static Induction Transistor의 순방향 블로킹 특성 개선에 관한 연구 (A Study on the Improvement of Forward Blocking Characteristics in the Static Induction Transistor)

  • 김제윤;정민철;윤지영;김상식;성만영;강이구
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2004년도 하계학술대회 논문집 Vol.5 No.1
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    • pp.292-295
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    • 2004
  • The SIT was introduced by Nishizawa. in 1972. When compared with high-voltage, power bipolar junction transistors, SITs have several advantages as power switching devices. They have a higher input impedance than do bipolar transistors and a negative temperature coefficient for the drain current that prevents thermal runaway, thus allowing the coupling of many devices in parallel to increase the current handling capability. Furthermore, the SIT is majority carrier device with a higher inherent switching speed because of the absence of minority carrier recombination, which limits the speed of bipolar transistors. This also eliminates the stringent lifetime control requirements that are essential during the fabrication of high-speed bipolar transistors. This results in a much larger safe operating area(SOA) in comparison to bipolar transistors. In this paper, vertical SIT structures are proposed to improve their electrical characteristics including the blocking voltage. Besides, the two dimensional numerical simulations were carried out using ISE-TCAD to verify the validity of the device and examine the electrical characteristics. A trench gate region oxide power SIT device is proposed to improve forward blocking characteristics. The proposed devices have superior electrical characteristics when compared to conventional device. Consequently, the fabrication of trench oxide power SIT with superior stability and electrical characteristics is simplified.

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Novel host and electron blocking materials for efficient and long lifetime phosphorescent OLEDs

  • Vestweber, Horst;Gerhard, Anja;Kaiser, Joachim;Heil, Holger;Kroeber, Jonas;Pflumm, Christof;Stoessel, Philipp;Joosten, Dominik;Buesing, Arne;Fortte, Rocco;Parham, Amir;Boehm, Edgar
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2008년도 International Meeting on Information Display
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    • pp.925-927
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    • 2008
  • In order to improve the performance in green phosphorescent OLED devices, Merck has developed novel host and electron blocking materials. The newly developed host materials improve the device lifetime by a factor of 3. The newly developed electron blocking materials having not only electron but also exciton barrier properties increase the efficiency of the device by a factor of 1.4. Comparable results were achieved in phosphorescent red systems with further host materials.

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A Novel Trench Electrode BRT with the Intrinsic Region for Power Electronics

  • Kang, Ey-Goo;Oh, Dae-Suk;Kim, Dae-Won;Kim, Dae-Jong;Sung, Man-Young
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 2002년도 ITC-CSCC -2
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    • pp.1038-1041
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    • 2002
  • In this paper, we have proposed a novel trench electrode Base Resistance Thyristor(BRT) and trench electrode BRT with a intrinsic region. A new power BRTs have shown superior electrical characteristics including snab-back effect and forward blocking voltage more than the conventional BRT Especially, the trench electrode BRT with intrinsic region has obtained high blocking voltage of 1600V. The blocking voltage of conventional BRT is about 400V at the same size. Because the breakdown mechanism of BRT is avalanch breakdown by impact ionization, the trench electrode BRT with intrinsic region has suppressed impact ionization, effectively. If we use this principle, we can develope super high voltage power device and applicate to another power device including IGBT, EST and etc,

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BAlq를 적용한 유기발광소자의 제작 및 특성 분석에 관한 연구 (A Study on the Fabrication and Characteristic Analysis of Organic Light Emitting Device using BAlq)

  • 오환술;황수웅;강성종
    • 한국전기전자재료학회논문지
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    • 제17권1호
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    • pp.83-88
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    • 2004
  • BAlq was fabricated as for hole blocking layer in the OLED devices to investigate its electrical and optical characteristics. Device structure was ITO/$\alpha$ -NPD/EML/BAlq/Alq3/Al:Li using TYG-201, DPVBi (4, 4 - Bis (2, 2 - diphenylethen-1 - yls) - Biphenyl), Alq and DCJTB (4-(dicyanomethylene)-2- (1-propyls)6-methy 4H-pyrans) as green emitting material, blue emitting material, host material for red emission and red emitting guest material respectively. The OLED device showed optimum working voltage and electron density at 600 cd/$m^2$ when thickness of BAlq is 25$\AA$ for RGB OLED devices while their efficiencies are better at 50$\AA$ of BAlq. Red and blue color OLEDs also fabricated using 30$\AA$ thickness of BAlq and compared with those without BAlq layer. BAlq was more effective in electrical properties such as working voltage, current density and efficiency of red OLED than blue and green ones. This study describes that 30$\AA$ is optimum thickness of BAlq for best performance of full color OLED devices when using BAlq as a hole blocking material.

정보통신기기용 과도이상전압 고속도차단장치의 설계 및 제작 (Design and Fabrication of a High Speed Blocking Device of Transient Overvoltages for info-communication Facilities)

  • 길경석
    • 대한전기학회논문지:전기물성ㆍ응용부문C
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    • 제48권1호
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    • pp.51-56
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    • 1999
  • This paper presents a new transient overvoltage blocking device (TOBD) for info-communication facilities with low power and high frequency bandwidth. Conventional protection devices have some problems such as low frequency bandwidth, low energy capacity and high remnant voltage. In order to improve these limitations, thehybrid type TOBD, which consists of a gas tube, avalanche diodes and junction typefield effect transistors (JFETs), was designed and fabricated. The TOBD differs from the conventional protection devices in configuration, and JFETs were used as an active non-linear element and a high speed switching diode with low capacitance limits high current. Therefore the avalanche dilde with low energy capacity are protected fromthe high current, and the TOBD has a very small input capacitance. From the performance test using combination surge generator, which can produce $1.2/50\mus\;4.2kV_{max}\; 8/20\mus\; 2.1kA_{max}$, it is confirmed that proposed TOBD has an excellent protection performance in tight clamping voltage and limiting current characteristics.

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Novel Host materials for Phosphorescent OLEDs with long lifetime

  • Kim, Young-Hoon;Yu, Eun-Sun;Kim, Nam-Soo;Jung, Sung-Hyun;Kim, Hyung-Sun;Lee, Ho-Jae;Kang, Eui-Su;Chae, Mi-Young;Chang, Tu-Won
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2008년도 International Meeting on Information Display
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    • pp.549-552
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    • 2008
  • We have developed a novel bipolar host material with both electron and hole transporting characteristics. Since CGH(Cheil Green Host) has some electron transporting characteristics, it shows increased luminance efficiency in device including TCTA and without HBL(hole blocking layer:BAlq). Maximum power efficency of CGH was 27.4lm/W at the device structure ITO/DNTPD(60)/NPB(20)/TCTA(10)/EML(30)/Alq3(20)/LIF(1)/Al. We measured device performance again without HBL. The result of CGH showing 26.0lm/W is outstanding compared to that of CBP showing 19.1lm/W without holeblocking layer. We also measured lifetime and found to be 205hr at 3000nit, that is significant result compared to the life time of CBP device showing 82hr. CGH shows high device performance with holeblocking layer. Moreover, it shows better device performance and life time than those of CBP without holeblocking.

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표면 전하에 의한 Thyristor 소자의 차단전압 및 누설전류특성 연구 (Study on the Blocking Voltage and Leakage Current Characteristic Degradation of the Thyristor due to the Surface Charge in Passivation Material)

  • 김형우;서길수;방욱;김기현;김남균
    • 대한전기학회논문지:전기물성ㆍ응용부문C
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    • 제55권1호
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    • pp.34-39
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    • 2006
  • In high-voltage devices such as thyristor, beveling is mostly used junction termination method to reduce the surface electric field far below the bulk electric field and to expand the depletion region thus that breakdown occurs in the bulk of the device rather than at the surface. However, coating material used to protect the surface of the device contain so many charges which affect the electrical characteristics of the device. And device reliability is also affected by this charge. Therefore, it is needed to analyze the effect of surface charge on electrical characteristics of the device. In this paper, we analyzed the breakdown voltage and leakage current characteristics of the thyristor as a function of the amount of surface charge density. Two dimensional process simulator ATHENA and two-dimensional device simulator ATLAS is used to analyze the surface charge effects.

엑시톤 억제층 두께에 따른 유기 광기전력 소자의 특성 (Properties in Organic Photovoltaic Cell Depending on the Exciton Blocking Layer Thickness)

  • 오현석;이준웅
    • 한국전기전자재료학회논문지
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    • 제18권12호
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    • pp.1148-1151
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    • 2005
  • Photovoltaic effects in organic solar cell were studied in a cell configuration of ITO/PEDOT:PSS/CuPc(20 nm)/$C_{60}$(40 nm)/BCP/Al(150 nm) at room temperature. Here, the BCP layer works as an exciton blocking layer. The exciton blocking layer must transport electrons from the acceptor layer to the metal cathode with minimal increase in the total cell series resistance and should absorb damage during cathode deposition. Therefore, a proper thickness of the exciton blocking layer is required for an optimized photovoltaic cell. Several thicknesses of BCP were made between $C_{60}$ and Al. And we obtained characteristic parameters such as short-circuit current, open-circuit voltage, and power conversion efficiency of the device under the illumination of AM 1.5.