• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.07b
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• pp.964-967
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• 2002

The effectiveness of silicon nitride SiNx surface passivation is investigated and quantified. This study adopted single-layer antireflection (SLAR) coating of SiNx for efficiency improvement of solar cell. The silicon nitride films were deposited by means of plasma enhanced chemical vapor deposition (PECVD) in planar coil reactor. The process gases used were pure ammonia and a mixture of silane and helium. The thickness and the refractive index on the films were measured by ellipsometry and chemical bonds were determined by using an FT-IR equipment. This films obtained were analyzed in term of hydrogen content, refractive index for gas flow ratio $(NH_3/SiH_4)$, and efficiency of solar cell. The polycrystalline silicon solar cells passivated by silicon nitride shows efficiency above 12.8%.

• 한국정보디스플레이학회:학술대회논문집
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• 2005.07b
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• pp.892-896
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• 2005

In this paper, key issues of stainless steel foil substrates for display applications have been described. We studied and analyzed technical issues on substrate passivation/planarization to control surface roughness and capacitive coupling from conductive substrates. A thick (either multiple or single) passivation/planarization layer needs to be applied on the nonelectronic-grade stainless steel substrate to provide a smooth surface and electrical insulation from the conductive substrate. Especially for large size, high-resolution display applications, low k and thick passivation/planarization layers should be used for appropriate capacitive coupling. Based on our initial study, a unit area capacitance of less than $2nF/cm^2$ of passivation/planarization layers is needed for 32" HD TV OLED displays.

• 한국정보디스플레이학회:학술대회논문집
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• 2009.10a
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• pp.594-596
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• 2009

Amorphous silicon nitride (a-SiNx) passivation film as a passivation layer of TFT-LCDs was deposited by AC-reactive sputtering at low temperature. As a result, the electrical characteristics and reliability of TFT with novel passivation showed the same level as the conventional TFT. Finally, we have developed 47"Full HD IPS TFT-LCDs with sputtered amorphous silicon nitride. It is suitable for low temperature based applications such as OTFT and Flexible display.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.08a
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• pp.299.2-299.2
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• 2013

We investigated the potassium remaining on a crystalline silicon solar cell after potassium hydroxide (KOH) etching and its effect on the lifetime of the solar cell. KOH etching is generally used to remove the saw damage caused by cutting a Si ingot; it can also be used to etch the rear side of a textured crystalline silicon solar cell before atomic layer-deposited Al2O3 growth. However, the potassium remaining after KOH etching is known to be detrimental to the efficiency of Si solar cells. In this study, we etched a crystalline silicon solar cell in three ways in order to determine the effect of the potassium remnant on the efficiency of Si solar cells. After KOH etching, KOH and tetramethylammonium hydroxide (TMAH) were used to etch the rear side of a crystalline silicon solar cell. To passivate the rear side, an Al2O3 layer was deposited by atomic layer deposition (ALD). After ALD Al2O3 growth on the KOH-etched Si surface, we measured the lifetime of the solar cell by quasi steady-state photoconductance (QSSPC, Sinton WCT-120) to analyze how effectively the Al2O3 layer passivated the interface of the Al2O3 layer and the Si surface. Secondary ion mass spectroscopy (SIMS) was also used to measure how much potassium remained on the surface of the Si wafer and at the interface of the Al2O3 layer and the Si surface after KOH etching and wet cleaning.

• Current Photovoltaic Research
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• v.7 no.4
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• pp.125-129
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• 2019

Recently, carrier-selective contact solar cells have attracted much interests because of its high efficiency with low recombination current density. In this study, we investigated the effect of phosphorus doped amorphous silicon layer's characteristics on the passivation properties of tunnel oxide passivated carrier-selective contact solar cells. We fabricated symmetric structure sample with poly-Si/SiOx/c-Si by deposition of phosphorus doped amorphous silicon layer on the silicon oxide with subsequent annealing and hydrogenation process. We varied deposition temperature, deposition thickness, and annealing conditions, and blistering, lifetime and passivation quality was evaluated. The result showed that blistering can be controlled by deposition temperature, and passivation quality can be improved by controlling annealing conditions. Finally, we achieved blistering-free electron carrier-selective contact with 730mV of i-Voc, and cell-like structure consisted of front boron emitter and rear passivated contact showed 682mV i-Voc.

• Journal of the Microelectronics and Packaging Society
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• v.19 no.1
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• pp.75-80
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• 2012

$InSb$ films were fabricated by DC magnetron sputtering and the effects of deposition temperature, heat treatment, passivation from evaporation and multi-layered structure were investigated. Electron mobility and electron concentration were linearly increased with deposition temperature for as-deposited specimens. It was found that the mobilities depend on the grain size rather than the stoichiometry for the samples with very low mobilities. The mobilities largely increased for the specimens with evaporation passivation compared with those without passivation layer. The mobility also increased with the amount of indium deposition in the multi-layer structured $InSb$ films. It was found that the mobility increments in both cases are due to the matching of the stoichiometry in $InSb$ films. For the heat treated and passivated specimens, the mobilities increased with annealing time and the maximum mobility was measured as 1612 $cm^2$/Vs.

• Journal of the Korean Vacuum Society
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• v.9 no.2
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• pp.144-149
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• 2000

Variables affecting the passivation capability of Cu(Mg) alloy films, which were sputter deposited from a Cu (4.5 at. %) target, have been investigated. The results show that the passivation capability of a Cu(Mg) alloy film is a function of annealing temperature, $O_2$ pressure, and Mg content in the film. Increasing the annealing temperature up to $500^{\circ}C$ favors formation of a dense MgO layer on the surface which has a growth limited thickness of 150 $\AA$. Decreasing the $O_2$ pressure enhances the preferential oxidation of Mg over Cu. Furthermore, increasing the Mg content in the Cu(Mg) film promotes formation of a dense MgO layer. Vacuum pre-annealing was found to be very effective in segregating Mg to the surface, facilitating the passivation capability of the Cu(Mg) alloy film even when the Mg content is low. In the current study, self-aligned MgO layers with low resistivity and an effective passivation capability over the Cu surface, have been obtained by manipulating these factors when Cu(Mg) thin films are annealed.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.22 no.3
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• pp.262-268
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• 2009

We investigated the properties of inorganic diatomic films like silicon oxide ($SiO_2$) and zinc oxide (ZnO) and their composite films are packed as a passivation layer around Ca cells on glass substrates by using an electron-beam evaporation technique and rf-magnetron sputtering method. When these Ca cells are exposed to an ambient atmosphere, the water vapor penetrating through the passivation layers is adsorbed in the Ca cells, resulting in a gradual progress of transparency in the Ca cells, which can be represented by changes of the optical transmittance in the visible range. Compared with the saturation times for the Ca cells to become completely transparent in the atmosphere, the protection effects against permeation of water vapor are estimated for various passivation films. The thin composite films consist of$SiO_2$ and ZnO are found to show a superior protection effect from water vapor permeation compared with diatomic inorganic films like $SiO_2$ and ZnO. Also, this inorganic thin composite films are also found that their protection effect against permeation of water vapor can be significantly enhanced by choosing their suitable composition ratio and deposition method, in addition, the main factors affecting the permeation of water vapor through the oxide films are found to be the polarizability and the packing density.

• Journal of the Korean institute of surface engineering
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• v.45 no.6
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• pp.219-225
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• 2012

The aim of the present study was to investigate the corrosion resistance and characteristics of passive layer between naturally passivated and chemically passivated duplex stainless steel, UNS S31803 (EN 1.4462) using CPT, XPS, and EIS. The treatment of $HNO_3$(II) and $HNO_3$(III) in ASTM A 967 was applied. In case of chemically passivated specimen, CPT of $HNO_3$(II) and $HNO_3$(III) were higher than that of naturally passivated specimen. In addition, from XPS results, the protectiveness index (Cr/(Fe+Cr)) of chemically passivated specimens was also higher than that of naturally passivated specimen. The reason for this result is considered due to post-cleaning treatment in chemical passivation process, that is, immersion in $Na_2Cr_3O_7$ solution. The fact that $HNO_3$(II) passivation treatment showed the highest film resistance and 'n', which is exponent related with constant phase element (CPE) of passivation film, was in good agreement with results of CPS and XPS. The chemical passivation treatment was an effective method to improve corrosion resistance of duplex stainless steel.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.54 no.11
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• pp.490-492
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• 2005

A study on radiation hardening of infrared(IR) detector, the chief component of IR camera was performed. The radiation test on IR sensor passivated with the ZnS by Co$^{60}$ gamma-ray over 1 Mrads showed the reduction in Ro by 1/100 which was related to the noise level. This effect that was caused by carrier trapping in the ZnS passivation layer increased the leakage current and resulted in degradation in the device performance. For the radiation hardening of IR devices we suggested the ones with CdTe passivation layer which had a tendency to reluctant to carrier trapping in its layer and developed test patterns. Radiation test to the patterns showed that the our CdTe passivated device could survived over 1 Mrad gamma-ray dose.