• 한국재료학회:학술대회논문집
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• 한국재료학회 2009년도 춘계학술발표대회
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• pp.16.2-16.2
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• 2009

Developing a low cost printing material that can replace silver for the formation of a conducting pattern is an important issue in printed electronics. We report a novel approach using a non-oxidized copper material during the printing and sintering process under ambient conditions, which was previously considered unachievable. An attempt was made to understand the conversion process of cuprous oxide nanoparticle aggregates on metallic copper crystals through chemical reduction in the solution phase. The detailed mechanism for this conversion, including the role of the surfactant and crystal growth, was examined.

• 한국전기전자재료학회논문지
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• 제29권12호
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• pp.819-823
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• 2016

DSSC (dye-sensitized solar cell) is expected to be one of the next-generation photovoltaics because of its environment-friendly and low-cost properties. However, commercialization of DSSC is difficult because of the electrolyte leakage. We propose thermal curable base on silicon resin and apply a unit cell and large area ($200{\times}200mm$) dye-sensitized solar cell. The resin aimed at sealing of DSSC and gives a promising resolution for sealing of practical DSSC. In result, the photoelectric conversion efficiency of the unit cell and the module was 6.63% and 5.49%, respectively. In the durability test result, the photoelectric conversion efficiency of the module during 500, 1,000, 1,500 and 2,000 hours was 0.73%, 0.73%, 1.82% and 2.36% respectively. It was confirmed that the photoelectric conversion efficiency characteristics are constant. We have developed encapsulation material of thermal curing method excellent in chemical resistance. A sealing material was applied to the dye-sensitized solar cell and it solved the problem of durability the dye-sensitized solar cell. Sealing material may be applied to verify the possibility of practical application of the dye-sensitized solar cell.

• 한국세라믹학회지
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• 제53권2호
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• pp.258-262
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• 2016

The effect of zirconium dioxide ($ZrO_2$) on the properties of color conversion glasses was examined in the $BaO-ZnO-B_2O_3-SiO_2$ system. The difference in refractive index between glass and phosphor affect the optical properties of the color conversion glass because of light scattering. Reducing the difference in refractive index is a method to improve the luminous efficacy of color conversion glasses. As a reference, a type of glass that contains 25 mol% of each component was used. To increase the refractive index of the glass samples, the BaO content was increased from 25 to 40 mol%, and $ZrO_2$ was added at levels of 1, 3, and 5 mol%. Color conversion glasses were prepared by sintering a mixture of glass and 5 wt% $YAG:Ce^{3+}$ phosphor. As a result, the refractive index of the glass was found to be dependent on the BaO and $ZrO_2$ contents in the BaO-ZnO-$B_2O_3-SiO_2$ system. As the BaO and $ZrO_2$ contents were increased, the luminous efficacy of the color conversion glass was improved because the refractive index difference between the glass and the $YAG:Ce^{3+}$ phosphor decreased.

• 마이크로전자및패키징학회지
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• 제25권3호
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• pp.21-30
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• 2018

Driven by the recent energy saving trend, conventional silicon based power conversion modules are being replaced by modules using silicon carbide. Previous papers have focused mainly on the electrical advantages of silicon carbide semiconductors that can be used to design switching devices with much lower losses than conventional silicon based devices. However, no systematic study of their thermomechanical reliability in power conversion modules using finite element method (FEM) simulation has been presented. In this paper, silicon and silicon carbide based power devices with three-phase switching were designed and compared from the viewpoint of thermomechanical reliability. The switching loss of power conversion module was measured by the switching loss evaluation system and measured switching loss data was used for the thermal FEM simulation. Temperature and stress/strain distributions were analyzed. Finally, a thermal fatigue simulation was conducted to analyze the creep phenomenon of the joining materials. It was shown that at the working frequency of 20 kHz, the maximum temperature and stress of the power conversion module with SiC chips were reduced by 56% and 47%, respectively, compared with Si chips. In addition, the creep equivalent strain of joining material in SiC chip was reduced by 53% after thermal cycle, compared with the joining material in Si chip.

• Current Photovoltaic Research
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• 제6권2호
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• pp.31-38
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• 2018

Multijunction solar cells present a practical solution towards a better photovoltaic conversion for a wider spectral range. In this review, we compare different types of multi-ijunction solar cell. First, we introduce thin film multijunction solar cell include to the thin film silicon, III-V material and chalcopyrite material. Until now the maximum reported power conversion efficiencies (PCE) of solar cells having different component sub-cells are 14.0% (thin film silicon), 46% (III-V material), 4.4% (chalcopyrite material) respectively. We then discuss the development of multijunction solar cell in which c-Si is used as bottom sub-cell while III-V material, thin film silicon, chalcopyrite material or perovskite material is used as top sub-cells.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2002년도 하계학술대회 논문집 Vol.3 No.2
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• pp.853-856
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• 2002

Present. direct method x-ray conversion detector is studied by abroad medical instrument and country with amorphous Selenium. And we search the method for large area x-ray detector. Amorphous-Selenium based photoreceptor is widely used on the X-ray conversion materials. But amorphous-selenium based x-ray conversion detector is broken by high voltage and leakage defect point. In this paper, We investigated top-electrode distance rate to improve defect point and high voltage broken. The result to appoint to made large area x-ray conversion detector with base data.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2002년도 하계학술대회 논문집 Vol.3 No.2
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• pp.904-907
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• 2002

In this study, the plasma-assisted $CO_2$ conversion characteristics were investigated in the streamer corona discharge and silent discharge reactors with dielectric of $Al_2O_3$, to improve the conversion efficiency $CO_2$. Some discharge characteristics of $CO_2$ as parameters of gap spacing and applied voltage frequency, in both corona and silent discharge reactor were also obtained. The maximum $CO_2$ conversion rate was 10.1 [%] under the 5.2 [W] of discharge power and 250 [Hz] of applied voltage frequency.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2010년도 하계학술대회 논문집
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• pp.246-246
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• 2010

In this study, the effect of wast heat-electric energy conversion according to temperature difference between two sides of a thermoelectric module was investigated as a way of electric energy conversion from waste heat generated in machinery system like automobile system.

• 한국전기전자재료학회논문지
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• 제21권4호
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• pp.311-320
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• 2008

In this paper, a 2.4 GHz low-voltage CMOS double-balanced down-conversion mixer using neutralization technique has been proposed and verified by circuit simulations and measurements. The grounded source structure was used for low-voltage operation. The neutralization technique was used to improve a conversion gain. The proposed mixer is fabricated in $0.25{\mu}m$ CMOS process for a 2.4 GHz wireless receiver. The mixer consumes 1.94 mW and gives conversion gain of 5.66 dB, input IP3 of 0.7 dBm and P1dB of -11.2 dBm at 1.5 V power supply. Measured results for the designed mixer show improved conversion gain of 2.86 dB over conventional mixer of grounded source structure.

• 대한기계학회논문집B
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• 제41권11호
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• pp.727-734
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• 2017

이산화탄소의 농도를 줄이는 방법 중 하나로 전기화학을 이용하여 이산화탄소를 고부가 가치인 탄소로 전환하는 연구가 진행 중이다. 본 연구에서는 4.0 V, $600^{\circ}C$의 실험 조건에서 은, 니켈, 백금, 이리듐 전극을 사용하였다. 720분 동안 이산화탄소의 전환을 수행하였으며, 각 전극에서 생성된 탄소는 열중량 분석 및 XRD 분석을 수행하였다. 이산화탄소의 전환 및 생성 탄소의 양은 은, 백금, 니켈, 이리듐으로 나타났다. 열중량 분석을 통해 각 전극에서 생성된 탄소는 유사한 열 반응성을 가지며, XRD 분석을 통해 전극의 반응성에 따라 탄소의 결정성이 달라짐을 확인할 수 있었다. 은 전극은 전기화학적 전환 성능은 가장 높지만 약한 내구성을 보이며, 전극의 반응성 및 내구성을 고려하였을 때 백금이 4개의 재질 중에서 가장 적합함을 확인하였다.