• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2010.06a
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• pp.355-355
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• 2010

We studied the dependence of the performance of schottky barrier metal-oxide-field effect transistors(SB MOSFETs) on the work function of source/drain metals. A strong impact of the various work functions and the light wavelengths on the transistor characteristics is found and explained using experimental data. We used an insulator of a high thickness (100nm) and back gate issues in SOI substrate, subthreshold swing was measured to 300~400[mV/dec] comparing with a ideal subthreshold swing of 60[mV/dec]. Excellent characteristics of Al/Si was demonstrated higher on/off current ratios of ${\sim}10^7$ than others. In addition, extensive photoresponse analysis has been performed using halogen and deuterium light sources(200<$\lambda$<2000nm).

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2010.06a
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• pp.249-249
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• 2010

We investigated novel surface treatment and its impact on silicon photovoltaic cells. Using 2-step etching methods, we have changed the nanostructure on pyramid surface so that less light is reflected. This work proposes an improved texturing technique of mono crystalline silicon surface for solar cells with sub-nanotexturing process. The nanotextured silicon surface exhibits a lower average reflectivity (~4%) in the wavelength range of 300-1100nm without antireflection coating layer. It is worth mentioning that the surface of pyramids may also affect the surface reflectance and carrier lifetime. In one word, we believe nanotextruing is a promising guide for texturization of monocrystalline silicon surface.

• The Korean Journal of Food And Nutrition
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• v.23 no.1
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• pp.114-117
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• 2010

The effects of isolated soy protein(ISP) content on the physicochemical properties of extrudates from rice flour produced by a single-screw extruder were evaluated. The integrity index(II), nitrogen solubility index(NSI), rehydration ratio(RR), and density were measured as indices of the changes of physicochemical properties of rice extrudates. Increased amounts of ISP resulted in increased II but decreased RR and density. There was no change in the NSI value. It was concluded that the addition of ISP to the raw material could be helpful in texturization of rice extrudate.

• Proceedings of the Korean Vacuum Society Conference
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• 2014.02a
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• pp.287.2-287.2
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• 2014

PV (photovoltaic) has becoming an important industry to invest due to its high robustness and require very little maintenance which goes a long time. Solar cell fabrication involves a few critical processes such as doping to make the N-type and P-type silicon, contact metallization, surface texturization, and anti-reflection coatings. Anti-reflection coating is a kind of surface passivation which ensures the stability, and efficiency of the solar cell. Thus, I will focus on the changes happen to the solar cell due to the reflectance and anti-reflection coating by PC1D. By using the PC1D (solar cell simulation program), I would analysis the effect of reflectance on the N-type cell. At last I will conclude the result regarding what I learned throughout this experiment.

• Journal of the Korean Society of Food Science and Nutrition
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• v.45 no.8
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• pp.1170-1176
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• 2016

The aim of this study was to investigate the effects of screw speed, moisture content, and die temperature on the physical properties of extruded soy protein isolate. Extrusion conditions were moisture content (20 and 25%) and die temperature (120, 130, and $140^{\circ}C$) at a fixed screw speed of 250 rpm. The other extrusion conditions for screw speed (150, 200, 250, 300, and 330 rpm) were a fixed moisture content and die temperature of 30% and $140^{\circ}C$, respectively. Specific mechanical energy input decreased as die temperature increased from 120 to $140^{\circ}C$, whereas specific mechanical energy input increased as screw speed increased from 150 to 330 rpm. Expansion ratio and specific length increased as die temperature increased. Breaking strength decreased as die temperature increased and moisture content decreased. A lower moisture content resulted in a greater color difference. Integrity index increased as die temperature increased from 120 to $140^{\circ}C$ and moisture content decreased from 25 to 20%. Nitrogen solubility index decreased as screw speed increased from 150 to 330 rpm. Nitrogen solubility index was lowest at $2.83{\pm}0.51%$ as screw speed decreased to 150 rpm. In conclusion, moisture content was a more important factor than die temperature for texturization of soy protein isolate.

• Proceedings of the Korean Vacuum Society Conference
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• 2016.02a
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• pp.419-419
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• 2016

High efficiency silicon solar cell requires the textured front surface to reduce reflectance and to improve the light trapping. In case of mono-crystalline silicon solar cell, wet etching with alkaline solution is widespread. However, the alkali texturing methods are ineffective in case of multi-crystalline silicon wafer due to grain boundary of random crystallographic orientation. The acid texturing method is generally used in multi-crystalline silicon wafer to reduce the surface reflectance. However the acid textured solar cell gives low short-circuit current due to high reflectivity while it improves the open-circuit voltage. To reduce the reflectivity of multi-crystalline silicon wafer, double texturing method with combination of acid and reactive ion etching is an attractive technical solution. In this paper, we have studied to optimize RIE experimental condition with change of RF power (100W, 150W, 200W, 250W, 300W). During experiment, the gas ratio of SF6 and O2 was fixed as 30:10.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2006.11a
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• pp.19-20
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• 2006

Two methods that can reduce reflectance in solar cells are surface texturing and anti-reflection coating. Wet chemical etching is a typical method that surface texturing of multi-crystalline silicon. Wet chemical etching methods are the acid texturization of saw damage on the surface of multi-crystalline silicon or double-step chemical etching after KOH saw damage removal too. These methods of surface texturing are realized by chemical etching in acid solutions HF-$HNO_3$-$H_2O$. In this solutions we can reduce reflectance spectra by simple process etching of multi-crystalline silicon surface. We have obtained reflectance of 27.19% m 400~1100nm from acidic chemical etching after KOH saw damage removal. This result is about 7% less than just saw damage removal substrate. The surface morphology observed by microscope and scanning electron microscopy (SEM).

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.26 no.2
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• pp.140-143
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• 2013

Lowering surface reflectance of silicon wafer by texturization is one of the most important processes to improve the efficiency of silicon solar cells. Generally, the texturing of crystalline silicon was carried out using alkaline solution. The average reflectance of this method was 11% at the wavelength between 400 and 1,000 nm. In this study, the wafers were first texturing by NaOH solution at $80^{\circ}C$ for 35 min. Then the wafers were texturing by $SF_6$ and $O_2$ plasma in RIE (Reactive Ion Etching). The average reflectance of two step texturing was reduced to below 5% at the wavelength between 400 and 1,000 nm.

• Food Science and Preservation
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• v.31 no.1
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• pp.46-63
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• 2024

This study evaluated the impact of storage temperature on the quality characteristics of texturized vegetable protein (TVP). TVP was prepared by mixing defatted Daewon soybean flour at 80℃, gluten, and corn starch in a 5:3:2 ratio, which was then extruded at a screw speed of 250 rpm and a barrel temperature of 190℃ with moisture addition at 9 rpm. Subsequently, the extruded TVP was vacuum-sealed in polyethylene packaging and stored at -20℃, 0℃, and 4℃ for 9 days. Texture analysis revealed that the curing rate followed 4℃ > 0℃ > -20℃ sequence. No significant color variation was observed across the storage conditions, although water content increased at all temperatures. Notable changes were detected in moisture absorption capacity (%) and solid leaching (%), following the order of -20℃ > 0℃ > 4℃. The turbidity of the solution released during cooking varied, with the highest to the lowest sequence being -20℃ > 4℃ > 0℃, while pH levels remained neutral. Regarding free amino acids, sweetness and textural quality improved with storage across all temperatures, whereas bitterness components diminished at 4℃. The study suggests that refrigerated storage at 4℃ is a viable method for distributing TVP, which was previously distributed only in a frozen and dry state.

• Korean Journal of Food Science and Technology
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• v.52 no.4
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• pp.357-362
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• 2020

This study was conducted to investigate the effects of mushroom composition (0, 4, 8, and 12%) on the quality characteristics of an extruded meat analog. The meat analog blend was isolated soy protein, wheat gluten, and corn starch (50:40:10). The extrusion condition was set to 55% feed moisture, 170℃ barrel temperature, and 150 screw speed by high moisture extrusion using a twin-screw extruder equipped with a cooling die. The integrity index, hardness, cohesiveness, springiness, chewiness, and cutting strength of the meat analog increased with the increasing mushroom content, while its water holding capacity and nitrogen solubility index (NSI) decreased. The protein digestibility decreased with the increasing mushroom content, while the DPPH radical scavenging activity significantly increased. In conclusion, the incorporation of mushrooms into the investigated meat analog enhanced its texture and antioxidant level.