• Title/Summary/Keyword: Cheongju-si

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A Study on LCL Circuit for Satellite Power System Applying WBG Device (WBG 소자를 적용한 위성 전력 시스템용 LCL 회로에 관한 연구)

  • Yoo, Jeong Sang;Ahn, Tae Young;Gil, Yong Man;Kim, Hyun Bae;Park, Sung Woo;Kim, Kyu Dong
    • Journal of the Semiconductor & Display Technology
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    • v.21 no.2
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    • pp.101-106
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    • 2022
  • In this paper, WBG semiconductor such as SiC and GaN were applied as power switches for LCL circuit that can be applied to satellite power systems and the test results of the LCL circuit are reported. P-channel MOSFET and N-channel MOSFET, which were generally used in the conventional LCL circuit, were applied together to expand the utility of the test results. The design and stability evaluation were performed using a Micro Cap circuit simulation program. For the test circuit, a module using each switch was manufactured, and a total of 5 modules were manufactured and the steady state and transient state characteristics were compared. From the experimental results, the LCL circuit for power supply of the satellite power system constructed in this paper satisfied the constant current and constant voltage conditions under various operating conditions. The P-channel MOSFET showed the lowest efficiency characteristics, and the three N-channel switches of Si, SiC and GaN showed relatively high efficiency characteristics of up to 99.05% or more. In conclusion, it was verified that the on-resistor of the switch had a direct effect on the efficiency and loss characteristics.

Improvement of Solar Conversion Efficiency in a c-Si PV Sub-Module Integrated with SiOx Anti-Reflection Grating for Oblique Optical Irradiation (측면입사광에 대한 SiOx 무반사 회절격자 결합 c-Si PV 서브-모듈의 광전변환효율 향상)

  • Shim, Ji-Hyun;Kim, Jeha
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.30 no.5
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    • pp.325-330
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    • 2017
  • We fabricated 1-D and 2-D diffraction gratings of SiOx anti-reflection (AR) film grown on a quartz substrate and integrated them into a c-Si photovoltaic (PV) submodule. The light-trapping effect of the resulting submodules was studied in terms of the oblique optical incident angle, ${\theta}_i$. As the ${\theta}_i$ increased, solar conversion efficiency, ${\eta}$, was improved as expected by the increased optical transmission caused by the grating. For ${\theta}_i{\leq}30^{\circ}$, the relative solar conversion efficiency, ${\Delta}{\eta}$, of a 1-D SiOx (t=300 nm) grating, compared to that of a flat SiOx AR-coated integrated PV submodule, was improved very little, with a small variation of within 2%, but increased markedly for ${\theta}_i{\geq}40^{\circ}$. We observed a change of ${\Delta}{\eta}$ as large as 10.7% and 9.5% for the SiOx grating of period t=800 nm and 1200 nm, respectively. For a 2-D SiOx (t=300 nm) grating integrated PV submodule, however, the optical trapping behavior was similar in terms of ${\theta}_i$ but its variation was small, within ${\pm}1.0%$.

A study on the Efficiency characteristics of the CRM PFC using GaN FET (GaN FET를 적용한 CRM PFC의 효율특성에 관한 연구)

  • Gil, Young-Man;Choi, Hyun-Su;Jin, Gi-Seok;Ahn, Tae-Young;Jang, Jin-Haeng
    • Proceedings of the KIPE Conference
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    • 2014.07a
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    • pp.89-90
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    • 2014
  • Recently, one of the switching rectifiers, Power Factor Correction Circuit is often applied in rectification stage to get high efficient conversion of AC-DC SMPS However, it becomes important to select optimal semiconductor switch as well as to design optimal rectifier for achieving higher power conversion. We performed experiments with MOSFET, SiC and GaN FET that are widely used in 600 W Interleaved CRM PFC and include the data in this report. The results are presented for discrete semiconductor and integrated implementations of interleaved CRM PFC.

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Review of 2-terminal Perovskite/SHJ Tandem Junction Solar Cell Technology (2-Terminal Perovskite/SHJ 탠덤 태양전지 기술 검토)

  • Jang, Minkyu;Jeon, Youngwoo;Kim, Minje;Yi, Junsin;Park, Jinjoo
    • Current Photovoltaic Research
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    • v.10 no.3
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    • pp.84-89
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    • 2022
  • c-Si solar cells currently account for more than 90% of the solar energy market. Research on tandem junction solar cells to overcome efficiency limitations is drawing attention at a time when new technologies are being developed to secure the price competitiveness of silicon solar cells. Among several candidate materials for silicon-based tandem solar cells, perovskite has recently been studied as it is suitable for the ease of process as well as for its properties as a tandem solar cell material. In this study, we want to review the research trends and technology limitations of 2-T Perovskite/SHJ tandem junction solar cells.

Characteristic Properties of Organic Thin Film Surface on Si Semiconductor (XRD 분석과 FTIR 분석에 의한 비정질 박막의 특성 연구)

  • Oh, Teresa
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2007.06a
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    • pp.112-113
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    • 2007
  • $SiO_2$ 절연 박막위에 희석된 PMMA 유기물을 처리하였다. 유기물 처리량에 따른 $SiO_2$ 박막의 $620{\sim}1100\;cm^{-1}$ 영역의 FTIR 스펙트라를 분석한 결과 0.3~0.7%로 PMMA 처리된 박막에서 친핵성 반응이 밀어나는 것을 확인하였으며, 친핵성 반응이 일어나는 박막들에서 누설전류가 적었으며, 절연특성이 우수한 것을 확인하였다.

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IR Cut-off Filter Made of CeO2 and SiO2 Thin Films Coated on PMMA Substrate (PMMA 기판에 CeO2와 SiO2를 코팅하여 제작한 적외선 차단필터)

  • Yu, Yeon-Serk;Choi, Sang-Serk
    • Korean Journal of Optics and Photonics
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    • v.17 no.5
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    • pp.480-486
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    • 2006
  • Generally, IR cut-off filters for mobile phone is coated on the glass substrate at high temperature(above $300^{\circ}C$). In this work, we prepared IR cut-off filters on the poly(methyl methacrylate)(PMMA) substrates at low temperature(about $70^{\circ}C$ ). using the $CeO_2\;and\;SiO_2$ coatings by physical vapor deposition. The surface energies of coated and uncoated PMMA, and adhesive properties of IR cut-off filters coatings were examined using contact angle measurements. We demonstrate the improve of mobile phone optical system using these results.

Dielectric Characteristics due to the nano-pores of SiOCH Thin Flm (기공형성에 의한 SiOCH 박막의 유전 특성)

  • Kim, Jong-Wook;Park, In-Chul;Kim, Hong-Bae
    • Journal of the Semiconductor & Display Technology
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    • v.8 no.3
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    • pp.19-23
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    • 2009
  • We have studied dielectric characteristics of low-k interlayer dielectric materials was fabricated by plasma enhanced chemical vapor deposition (PECVD). BTMSM precursor was introduced with the flow rates from 24 sccm to 32 sccm by 2 sccm step in the constant flow rate of 60 sccm $O_2$. Then, SiOCH thin film deposited at room temperature was annealed at temperature of $400^{\circ}C$ and $500^{\circ}C$ for 30 minutes in vacuum. The vibrational groups of SiOCH thin films were analyzed by FT/IR absorption lines, and the dielectric constant of the low-k SiOCH thin films were obtained by measuring C-V characteristic curves. With the result that FTIR analysis, as BTMSM flow rate increase, relative carbon content of SiOCH thin film increased from 29.5% to 32.2%, and increased by 32.8% in 26 sccm specimen after $500^{\circ}C$ annealing. Dielectric constant was lowest by 2.32 in 26 sccm specimen, and decreased more by 2.05 after $500^{\circ}C$ annealing. Also, leakage current is lowest by $8.7{\times}10^{-9}A/cm^2$ in this specimen. In the result, shift phenomenon of chemical bond appeared in SiOCH thin film that BTMSM flow rate is deposited by 26 sccms, and relative carbon content was highest in this specimen and dielectric constant also was lowest value

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Fabrication and Properties of MIS Inversion Layer Solar Cell using $Al_2O_3$ Thin Film ($Al_2O_3$ 박막을 이용한 MIS Inversion Layer Solar Cell의 제작 및 특성평가)

  • Kim, Hyun-Jun;Byun, Jung-Hyun;Kim, Ji-Hun;Jeong, Sang-Hyun;Kim, Kwang-Ho
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2010.06a
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    • pp.242-242
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    • 2010
  • 산화 알루미늄($Al_2O_3$) 박막을 p-type Czochralski(CZ) Si 위에 Remote Plasma Atomic Layer Deposition(RPALD)을 이용하여 저온 공정으로 증착하였다. Photolithography 공정으로 grid 패턴을 형성한 후 열 증착기로 알루미늄을 증착하여 MIS-IL (Metal-Insulator-Semiconductor Inversion Layer) solar cell을 제작하였다. 반응소스로는 Trimethylaluminum (TMA)과 $O_2$를 이용하였다. $Al_2O_3$ 박막의 전기적 특성 평가를 위해 MIS capacitor를 제작하여 Capacitance-voltage (C-V), Current-voltage (I-V), Interface state density ($D_{it}$)를 평가하였으며 Solar simulator를 이용하여 MIS-IL Solar cell의 Efficiency을 측정하였다.

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Influence of Wet Annealing on the Performance of SiZnSnO Thin Film Transistors

  • Han, Sangmin;Lee, Sang Yeol
    • Transactions on Electrical and Electronic Materials
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    • v.16 no.1
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    • pp.34-36
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    • 2015
  • Amorphous SiZnSnO(SZTO) thin film transistors(TFTs) have been fabricated by RF magnetron sputtering process, and they were annealed in air and in wet ambient. The electrical performance and the structure were analyzed by I-V measurement, XPS, AFM, and XRD. The results showed improvement in device performance by wet annealing process compared to air annealing treatment, because free electron was shown to be increased due to reaction of oxygen and hydrogen generating oxygen vacancy. This is understood by the generation of free electrons. We expect the wet annealing process to be a promising candidate to contributing to high electrical performance of oxide thin film transistors for backplane device applications.

Influence of Channel Thickness Variation on Temperature and Bias Induced Stress Instability of Amorphous SiInZnO Thin Film Transistors

  • Lee, Byeong Hyeon;Lee, Sang Yeol
    • Transactions on Electrical and Electronic Materials
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    • v.18 no.1
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    • pp.51-54
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    • 2017
  • TFTs (thin film transistors) were fabricated using a-SIZO (amorphous silicon-indium-zinc-oxide) channel by RF (radio frequency) magnetron sputtering at room temperature. We report the influence of various channel thickness on the electrical performances of a-SIZO TFTs and their stability, using TS (temperature stress) and NBTS (negative bias temperature stress). Channel thickness was controlled by changing the deposition time. As the channel thickness increased, the threshold voltage ($V_{TH}$) of a-SIZO changed to the negative direction, from 1.3 to -2.4 V. This is mainly due to the increase of carrier concentration. During TS and NBTS, the threshold voltage shift (${\Delta}V_{TH}$) increased steadily, with increasing channel thickness. These results can be explained by the total trap density ($N_T$) increase due to the increase of bulk trap density ($N_{Bulk}$) in a-SIZO channel layer.