• Title/Summary/Keyword: Junction

Search Result 3,204, Processing Time 0.07 seconds

The characterization of crystalline silicon solar cell according to junction depth by using PC1D (PC1D를 이용한 junction depth에 따른 결정질 실리콘 태양전지의 특성 분석)

  • Lim, Jungkyu;Yi, Junsin
    • 한국신재생에너지학회:학술대회논문집
    • /
    • 2011.11a
    • /
    • pp.65.2-65.2
    • /
    • 2011
  • 일반적으로 결정질 실리콘 태양전지에서는 junction depth가 얕아짐으로써 단파장 영역에서의 수집효율이 향상되고 Jsc가 상승하기 때문에 junction depth가 얕은 것이 좋다. 또, 태양전지의 효율을 높이기 위해서는 낮은 재결합 속도가 필요한데 이를 위해서도 얕은 junction depth가 필요하다. 하지만 junction depth가 너무 얕으면 FF와 Voc가 낮아져 효율이 떨어지므로 junction depth를 최적화 할 필요가 있다. 본 논문에서는 PC1D 시뮬레이션을 사용하여 표면 농도를 고정시키고 junction depth를 가변하면서 이에 따른 cell의 parameter변화를 관찰하였다. 그 결과, 면저항 $120{\Omega}/{\square}$에서부터 효율이 saturation되었고, 그에 따른 parameter 값은 FF=76.28%, Jsc=$38.17mA/cm^2$, Voc=596.5V이며 junction depth가 $0.1726{\mu}m$일 때 효율은 17.37%이다.

  • PDF

The Fabrication of Super Junction IGBT with 3,000 V Class Super Junction Field Rings (3,000 V급 초접합 필드링을 갖는 초접합 IGBT 제작에 관한 연구)

  • Kang, Ey Goo
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
    • /
    • v.28 no.9
    • /
    • pp.551-554
    • /
    • 2015
  • This paper was analyzed electrical characteristics of super junction IGBT with super junction field rings. As a result of super junction IGBT with super junction field rings, we obtained 3,300 V breakdown voltage and good thermal characteristics. we obtained shrinked chip size because field ring was decreased than field ring for conventional IGBT, too. And we fabricated super junction IGBT with super junction field rings. As a result of measuring fabricated chip, we obtained 3,300 V breakdown voltage. The fabricated devices were replaced thyristos using high voltage conversion, sufficiently.

CONSERVATIVE FINITE VOLUME METHOD ON BOUNDARY TREATMENTS FOR FLOW NETWORK SYSTEM ANALYSES (유동망 시스템 해석을 위한 경계처리에 대한 보존형 유한체적법)

  • Hong, S.W.;Kim, C.
    • Journal of computational fluids engineering
    • /
    • v.14 no.1
    • /
    • pp.35-44
    • /
    • 2009
  • To adequately analyze flows in pipe or duct network system, traditional node-based junction coupling methods require the junction loss which is specified by empirical or analytic correlations. In this paper, a new finite volume junction coupling method using a ghost junction cell is developed by considering the interchange of linear momentum as well as the important wall-effect at junction without requiring any correlation on the junction loss. Also, boundary treatment is modified to preserve the stagnation enthalpy across boundaries, such as pipe-end and the interface between junction and branch. Also, the computational accuracy and efficiency of the Godunov-type finite volume schemes are investigated by tracing the total mechanical energy of rapid transients due to sudden closure of valve at downstream end.

A study on I-V characteristics in JBS rectifiers according to PN junction structures (JBS(Junction Barrier-controlled Schottky)정류기의 PN접합구조에 따른 I-V 특성에 관한 연구)

  • 안병목;정원채
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
    • /
    • v.13 no.1
    • /
    • pp.13-20
    • /
    • 2000
  • In this paper, we demonstrated an analytical description method of forward votage drop and reverse leakage current of the junction barrier controlled schottky rectifier with linearly graded junction and abrupt junction models. In this case, the vertical depths of device are 1[${\mu}{\textrm}{m}$] and 2[${\mu}{\textrm}{m}$], respectively. Through ion implantation and annealing process, we obtain the data of lateral and depth from implanted 2-dimensional profiles. Also we applied these data to models that indicate the change of depletion each on linearly-graded and abrupt juction as the forward and revers bias. After applied depletion changes to electric characteristics of JBS rectifiers, we calculated the forward I-V, the reverse leakage current and temperatures vs. power dissipations according to each junction. When we compared the rectifier with calculated and measured data, from the calculated results, forward votage drop with linearly graded junction is lower than that of abrupt junction and reverse leakage current with linearly graded junction is lower(≒1$\times$10\ulcorner times) than that of abrupt junction. Also, the power dissipations according to different juction depth(1[${\mu}{\textrm}{m}$], 2[${\mu}{\textrm}{m}$]) of device are calculated. Seeing the calculated results, we confirmed it from analytic model that the rectifier with linearly graded junction retained a low power dissipation up to 600[$^{\circ}C$] in comparison with the rectifier with abrupt junction.

  • PDF

Comparison of Drain-Induced-Barrier-Lowering (DIBL) Effect by Different Drain Engineering

  • Choi, Byoung-Seon;Choi, Pyung-Ho;Choi, Byoung-Deog
    • Proceedings of the Korean Vacuum Society Conference
    • /
    • 2012.02a
    • /
    • pp.342-343
    • /
    • 2012
  • We studied the Drain-Induced-Barrier-Lowering (DIBL) effect by different drain engineering. One other drain engineering is symmetric source-drain n-channel MOSFETs (SSD NMOSs), the other drain engineering is asymmetric source-drain n-channel MOSFETs (ASD NMOSs). Devices were fabricated using state of art 40 nm dynamic-random-access-memory (DRAM) technology. These devices have different modes which are deep drain junction mode in SSD NMOSs and shallow drain junction mode in ASD NMOSs. The shallow drain junction mode means that drain is only Lightly-Doped-Drain (LDD). The deep drain junction mode means that drain have same process with source. The threshold voltage gap between low drain voltage ($V_D$=0.05V) and high drain voltage ($V_D$=3V) is 0.088V in shallow drain junction mode and 0.615V in deep drain junction mode at $0.16{\mu}m$ of gate length. The DIBL coefficients are 26.5 mV/V in shallow drain junction mode and 205.7 mV/V in deep drain junction mode. These experimental results present that DIBL effect is higher in deep drain junction mode than shallow drain junction mode. These results are caused that ASD NMOSs have low drain doping level and low lateral electric field.

  • PDF

Junction termination technology for 4H-SiC devices (Junction termination 기법에 따른 4H-SiC 소자의 항복전압 특성 분석)

  • Kim, H.Y.;Bahng, W.;Song, G.H.;Kim, N.K.;Kim, E.D.
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
    • /
    • 2003.07a
    • /
    • pp.286-289
    • /
    • 2003
  • In the case of high voltage devices, junction termination plays an important role in determining the breakdown voltage of the device. The mesa junction termination has been demonstrated to yield nearly ideal breakdown voltage for 6H-SiC p-n junctions. However, such an approach may not be attractive because of the nonplanar surface, which is difficult to passivate. Moreover, In case of 4H-SiC, ideal breakdown voltage could not be achieved using mesa junction termination. For 4H-SiC planar junction termination technique is more useful one rather than mesa junction termination. In this paper, breakdown characteristics of the 4H-SiC device with planar junction termination, such as FLR(Field Limiting Ring), FP(Field Plate) and JTE(Junction Termination Extension), is presented. In the case of the FLR, breakdown voltage of 1800V is obtained. And breakdown voltage of 1000V and 1150V is also obtained for the case of FP and JTE case, respectively.

  • PDF

A Study of the Improvement of Thermal Performance of a Junction Box of a Passenger Car (자동차 정션박스의 열성능 개선을 위한 연구)

  • Lee, Young-Lim
    • Transactions of the Korean Society of Automotive Engineers
    • /
    • v.16 no.2
    • /
    • pp.136-142
    • /
    • 2008
  • Thermal management of a junction box of a passenger car has recently become more challenging due to its smaller size and larger current capacity. Thus, it is essential to perform the thermal optimization of a junction box in its design on an early stage of vehicle design. In this study, 3 dimensional CFD simulation with experimental measurement has been done to study for better thermal management of the junction box. First, the study of thermal characteristics of electric relays in the junction box has revealed that each surface of the relay has very different thermal resistance. In addition, an idea to install a cooling fan on the junction box has been studied and it was found that the forced cooling method was not effective on the system to keep the thermal resistance to the reasonable level of the junction box. Finally, the effect of external flows around the junction box on the temperatures of the relays, fuses, etc. has been studied and the result shows that the installation of the junction box at the proper place in an engine room can avoid any unnecessary overdesign in thermal management.

Assessment Methodology of Junction Temperature of Light-Emitting Diodes (LEDs)

  • Chang, Moon-Hwan;Pecht, Michael
    • Journal of the Microelectronics and Packaging Society
    • /
    • v.23 no.3
    • /
    • pp.7-14
    • /
    • 2016
  • High junction temperature directly or indirectly affects the optical performance and reliability of high power LEDs in many ways. This paper is focused on junction temperature characterization of LEDs. High power LEDs (3W) were tested in temperature steps to reach a thermal equilibrium condition between the chamber and the LEDs. The LEDs were generated by pulsed currents with duty ratios (0.091% and 0.061%) in multiple steps from 0mA and 700mA. The diode forward voltages corresponding to the short pulsed currents were monitored to correlate junction temperatures with the forward voltage responses for calibration measurement. In junction temperature measurement, forward voltage responses at different current levels were used to estimate junction temperatures. Finally junction temperatures in multiple steps of currents were estimated in effectively controlled conditions for designing the reliability of LEDs.

Development of a Junction between Airport Concrete and Asphalt Pavements (공항 콘크리트와 아스팔트 포장 간의 접속 방법 개발)

  • Park, Hae Won;Kim, Dong Hyuk;Jeong, Jin Hoon
    • International Journal of Highway Engineering
    • /
    • v.20 no.4
    • /
    • pp.15-20
    • /
    • 2018
  • PURPOSES : The purpose of this study is to analyze the magnitude of shoving of asphalt pavement by junction type between airport concrete and asphalt pavements, and to suggest a junction type to reduce shoving. METHODS : The actual pavement junction of a domestic airport, which is called airport "A" was modified by placing the bottom of the buried slab on the top surface of the subbase. A finite element model was developed that simulated three junction types: a standard section of junction proposed by the FAA (Federal Aviation Administration), an actual section of junction from airport "A" and a modified section of junction from airport "A". The vertical displacement of the asphalt surface caused by the horizontal displacement of the concrete pavement was investigated in the three types of junction. RESULTS : A vertical displacement of approximately 13 mm occurred for the FAA standard section under horizontal pushing of 100 mm, and a vertical displacement of approximately 55 mm occurred for the actual section of airport "A" under the same level of pushing. On the other hand, for the modified section from airport "A" a vertical displacement of approximately 17 mm occurred under the same level of pushing, which is slightly larger than the vertical displacement of the FAA standard section. CONCLUSIONS : It was confirmed that shoving of the asphalt pavement at the junction could be reduced by placing the bottom of the buried slab on the top surface of the subbase. It was also determined that the junction type suggested in this study was more advantageous than the FAA standard section because it resists faulting by the buried slab that is connected to the concrete pavement. Faulting of the junctions caused by aircraft loading will be compared by performing finite element analysis in the following study.

The Improvement of Junction Box Within Photovoltaic Power System

  • Sun, Ki-Ju;Cheon, Min-Woo
    • Transactions on Electrical and Electronic Materials
    • /
    • v.17 no.6
    • /
    • pp.359-362
    • /
    • 2016
  • In the PV (Photovoltaic) power system, a junction box collects the DC voltage generated from the PV module and transfers it to the PCS (power conditioning system). The junction box prevents damage caused by the voltage difference between the serially connected PV modules and provides convenience while repairing or inspecting the PV array. In addition, the junction box uses the diode to protect modules from the inverse current when the PV power system and electric power system are connected for use. However, by using the reverse blocking diode, heat is generated within the junction box while generating electric power, which decreases the generating efficiency, and causes short circuit and electric leakage. In this research, based on the purpose of improving the performance of the PV module by decreasing the heat generation within the junction box, a junction box with a built-in bypass circuit was designed/manufactured so that a certain capacity of current generated from the PV module does not run through the reverse blocking diode. The manufactured junction box was used to compare the electric power and heating power generated when the circuit was in the bypass/non-bypass modes. It was confirmed that the electric power loss and heat generation indicated a decrease when the circuit was in the bypass mode.