• 한국진공학회:학술대회논문집
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• 한국진공학회 2016년도 제50회 동계 정기학술대회 초록집
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• pp.426.1-426.1
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• 2016

We report high work function Aluminum doped zinc oxide (AZO) films as insertion layer as a function of O2 flow rate between transparent conducting oxides (TCO) and hydrogenated amorphous silicon oxide (a-SiOx:H) layer to improve open circuit voltage (Voc) and fill factor (FF) for high efficiency thin film solar cell. However, amorphous silicon (a-Si:H) solar cells exhibit poor fill factors due to a Schottky barrier like impedance at the interface between a-SiOx:H windows and TCO. The impedance is caused by an increasing mismatch between the work function of TCO and that of p-type a-SiOx:H. In this study, we report on the silicon thin film solar cell by using as insertion layer of O2 reactive AZO films between TCO and p-type a-SiOx:H. Significant efficiency enhancement was demonstrated by using high work-function layers (4.95 eV at O2=2 sccm) for engineering the work function at the key interfaces to raise FF as well as Voc. Therefore, we can be obtained the conversion efficiency of 7 % at 13mA/cm2 of the current density (Jsc) and 63.35 % of FF.

• 한국진공학회지
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• 제22권3호
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• pp.162-167
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• 2013

이종 p-InGaP/N-InAlGaP 접합 화합물 반도체 태양전지의 에피 구조를 제안하였다. 제안된 이종접합구조와 p-InGaP/p-GaAs/N-InAlGaP와 동종 p-InGaP/n-InGaP 접합구조 태양전지의 전류-전압 특성곡선을 시뮬레이션하고 결과를 비교분석하였다. 이종 p-InGaP/N-InAlGaP 접합구조에서 가장 높은 최대출력과 곡선인자(fill factor)를 나타내는 시뮬레이션 결과를 얻었으며 이를 바탕으로 제안된 이종접합 에피구조를 최적화하였다.

• E2M - 전기 전자와 첨단 소재
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• 제8권4호
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• pp.406-412
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• 1995

A n-CdS thin films were evaporated by thermal evaporation method and their structure, optical transmission spectra and electrical characteristics were investigated. The photovoltaic characteristics of solar cells which were fabricated in optimum conditions measured. The evaporated CdS thin films showed in hexagonal structure and above 80% of optical transmission spectra regardless of impurity doping. The high quality thin films could be obtained at 150.deg. C temperature of substrate, which is useful for solar cell window layer with low resistivity of 6*10$\^$-2/(.ohm.-cm) by In doping We measured the electrical and optical characteristics of the n-CdS/p-InP heterojunction solar cells. The most efficient photovoltaic characteristics of heterojunction solar cells had the open circuit voltage of 0.66V, short circuit current density of 13.85mA/cm$\^$2/, fill factor of 0.576 and conversion efficiency of 8.78% under 60mW/cm$\^$2/ illumination.

• 신재생에너지
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• 제2권3호
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• pp.31-36
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• 2006

Superstrate pin amorphous silicon thin-film(a-Si:H) solar cells are prepared on $SnO_2:F$ and ZnO:Al transparent conducting oxides(TCO) in order to see the effect of TCO/p-layers on a-Si:H solar cell operation. The solar cells prepared on textured ZnO:Al have higher open circuit voltage VOC than cells prepared on $SnO_2:F$. Presence of thin microcrystalline p-type silicon layer(${\mu}c-Si:H$) between ZnO:Al and p a-SiC:H plays a major role by causing improvement in fill factor as well as $V_{OC}$ of a-Si:H solar cells prepared on ZnO:Al TCO. Without any treatment of pi interface, we could obtain high $V_{OC}$ of 994mV while keeping fill factor(72.7%) and short circuit current density $J_{SC}$ at the same level as for the cells on $SnO_2:F$ TCO. This high $V_{OC}$ value can be attributed to modification in the current transport in this region due to creation of a potential barrier.

• 한국농공학회:학술대회논문집
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• 한국농공학회 2000년도 학술발표회 발표논문집
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• pp.477-483
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• 2000

Fly ash is the unburned residue resulting from the combustion of coal in utility and industrial boilers such as thermal power plants. Annually about 5 million tons of fly ash is being produced in korea. Less than 25 percent of total volume of fly ash is currently being used effectively for some ways. In the future, the volume of fly ash discharge from thermal power stations will be increasing more and more, and the development of the utilization of high volume fly ash is required. Fly ash has a lower compacted density and specific gravity than coarse grained natural aggregates but equivalent strength properties indicating that the fly ash could be used as a structural fill materials. So, clay-fly ash mixtures can be used as a fill material in the construction of embankments. Laboratory tests have been carried out to determine the physical, chemical, and geotechnical characteristics of the clay and fly ash. The fly ash is mixed with the clay in different proportions and the geotechnical characteristics of the mixtures have been studied also. In this study describes the results of the experimental study. The implications of the use of clay and clay-fly ash mixtures on the stability of embankments are discussed.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2006년도 춘계학술대회
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• pp.158-161
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• 2006

Superstrate pin amorphous silicon thin-film (a-Si:H) solar cells are prepared on $SnO_2:F$ and ZnO:Al transparent conducting oxides (TCO) In order to see the effect of TCO/P-layers on a-Si:H solar cell operation. The solar cells prepared on textured ZnO:Al have higher open circuit voltage $V_{oc}$ than cells prepared on $SnO_2:F$. Presence of thin microcrystalline p-type silicon layer $({\mu}c-Si:H)$ between ZnO:Al and p a-SiC:H plays a major role by causing improvement in fill factor as well as $V_{oc}$, of a-Si:H solar cells prepared on ZnO:Al TCO. Without any treatment of pi interface, we could obtain high $V_{oc}$, of 994mv while keeping fill factor (72.7%) and short circuit current density $J_{sc}$ at the same level as for the cells on $SnO_2:F$ TCO. This high $V_{oc}$ value can be attributed to modification in the current transport in this region due to creation of a potential barrier.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2014년도 제46회 동계 정기학술대회 초록집
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• pp.471.2-471.2
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• 2014

We demonstrate here that an improvement in precursor film density (green density) leads to a great enhancement in the photovoltaic performance of CuInSe2 (CISe) thin film solar cells fabricated with Cu-In nanoparticle precursor films via chemical solution deposition. A cold-isostatic pressing (CIP) technique was applied to uniformly compress the precursor film over the entire surface (measuring 3~4 cm2) and was found to increase its relative density (particle packing density) by ca. 20%, which resulted in an appreciable improvement in the microstructural features of the sintered CISe film in terms of lower porosity, reduced grain boundaries, and a more uniform surface morphology. The low-bandgap (Eg=1.0 eV) CISe PV devices with the CIP-treated film exhibited greatly enhanced open-circuit voltage (VOC, from 0.265 V to 0.413 V) and fill factor (FF, from 0.34 to 0.55), as compared to the control devices. As a consequence, an almost 3-fold increase in the average power conversion efficiency, 3.0 to 8.2% (with the highest value of 9.02%), was realized without an anti-reflection coating. A diode analysis revealed that the enhanced VOC and FF were essentially attributed to the reduced reverse saturation current density (j0) and diode ideality factor (n). This is associated with the suppressed recombination, likely due to the reduction in recombination sites such as grain/air surfaces (pores), inter-granular interfaces, and defective CISe/CdS junctions in the CIP-treated device. From the temperature dependences of VOC, it was confirmed that the CIP-treated devices suffer less from interface recombination.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2012년도 제43회 하계 정기 학술대회 초록집
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• pp.423-423
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• 2012

Recently, many researchers made progress in various studies improving the efficiency of dye-sensitized solar cell. In this paper, we used glass textured by wet-chemical etching process for improvement of photocurrent density in dye-sensitized solar cells. This is owing to increase coefficient of light utilization. Consequently, DSSC using the textured glass exhibit a Jsc of 9.49 mA/$cm^2$, a Voc of 0.73 V and a fill factor (FF) of 0.67 with an overall conversion efficiency of 4.64. This result showed increasing of 20% current density and 16% conversion efficiency using the textured glass. These results suggested that glass texturing was very effective in controlling the light-scattering properties into the photovoltaic cell.

• 한국세라믹학회지
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• 제32권9호
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• pp.1047-1055
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• 1995

Mn-Zn ferrite granules were formed by a spray-drying method of the slurry containing different kinds and concentrations of binders at various temperatures. The slurry was made by conventional ceramic processing method, that is, by mixing Fe2O3, MnO, ZnO powders (52 : 24 : 24 mol%), calcining and milling. Typical shape of the spray dried granules was spherical. The compaction behavior of these granules was dependent on the spray-drying temperature and the kind and concentration of binders. At lower pressure the granules were displaced and at higher pressure the granules were deformed and fractured to fill pores among the granules. The optimum concentration of the binder was 0.5wt%. The granules containing 0.5wt% PVA 205 were deformed and fractured well and the green density was higher than others. At higher concentrations of the binder the granules were deformed rather than fractured, therefore the green density was lowered because of the remaining unfilled pores. The decomposition temperature and the heat released were increased with increasing the concentration of the binders. The compaction response of the granules containing PVA 205 was more efficient than those containing PVA 217 and PVA 117. Green density was not dependent on the degree of hydrolysis of the binders. The compaction response of the granules spray-dried at 15$0^{\circ}C$ was most efficient.

• 마이크로전자및패키징학회지
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• 제22권4호
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• pp.99-104
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• 2015

비아 필링에 있어서 void나 seam 생성이 없이 비아를 채우는 것은 매우 중요한 사항으로 전류밀도, 전류모드, 첨가제 등을 변화시켜 결함없는 비아를 얻어왔다. 그러나 다양한 첨가제의 부산물이 오염의 원인이 되며 도금액의 수명을 줄이는 문제점이 있었다. 본 연구에서는 오염을 최소화하기 위하여 다른 첨가제가 없이 JGB만을 사용하여 JGB 농도와 전류밀도 변화에 따른 비아 필링 현상을 연구하였다. 지름이 $15{\mu}m$이며 종횡비 4인 비아가 사용되었으며 펄스전류를 이용하여 도금을 하였다. 전류밀도는 $10{\sim}20mA/cm^2$, JGB 농도는 0~25 ppm까지 변화시키면서 JGB 농도와 전류밀도와 의 상관관계를 mapping 하였다. 그로부터 지름이 $15{\mu}m$이며 종횡비 4인 비아 필링의 최적 조건을 확립하였다.