• Proceedings of the Korean Vacuum Society Conference
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• 2012.02a
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• pp.304-304
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• 2012

CIGS(CuInGaSe2) 태양전지의 후면전극(Back contact)으로 널리 사용되는 Mo 박막은 낮은 면저항, 높은 반사율, 광흡수층 Na-path 제공 등의 조건이 요구된다. 일반적으로 Mo 박막 제작은 DC 마그네트론 스퍼터링 방법이 가장 널리 사용되며, 제작조건에 따라 태양전지 효율에 강한 영향을 미치는 것으로 보고되고 있다. 본 연구에서는 DC 마그네트론 스퍼터링 시 기판에 이온빔(Ion-beam)을 동시 조사하는 이온 빔 스퍼터링 증착(Ion-beam sputter deposition)법으로 Mo 박막을 제작하였다. 제작된 박막의 전기적 및 광학적 특성은 4-point probe, UV-Vis-NIR spectrometer로 각각 조사하였으며 Na-path 제어를 위한 구조적 특성은 XRD, FE-SEM으로 분석하였다. 분석결과에 따르면 기존 DC 마그네트론 스퍼터링 방법보다 상대적으로 더 치밀한 구조와 높은 반사율을 가지는 박막이 제작됨을 알 수 있었다. Mo 박막의 최적조건은 DC power 300 W, Ion-gun power 50 W, Ar flow rate 20 sccm 였다.

• Korean Journal of Materials Research
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• v.10 no.8
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• pp.564-568
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• 2000

Langmuir-Blodgett(LB) 법은 미래의 분자전자소자를 위한 가장 유력한 수단이며, 이러한 분자박막 소자는 그 성질이 분자는 배향에 영향을 박데 되므로 현재 새로운 물질을 이용하여 분자전자소자의 제작에 있어 관심을 모으고 있다. 본 연구에서는 (N-docosyl quinolinium)-TCNQ(1:2) 전하 이동 착물 LB 막의 분자 배향을 UV/vis 편광흡수 스펙트럼과 FT-IR transmission 및 reflection-absorption 스펙트럼의 흡수강도를 비교하여 정량적으로 평가하였다. 그 결과 TCNQ의 transition dipole moment의 각은 약 56~58。 였으며, 알킬 고리의 경사각은 약 11.1~13。였다. 제작된 Z-형 LB 막의 표면은 고압에서 중앙 높이 차가 3~4$\AA$으로 평탄하였다.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.15 no.2
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• pp.153-161
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• 2002

Stable polyaniline-dodecylbenzenesulfonic acid(PANI-DBSA) fully dissolved in toluene was obtained by a direct one-step emulsion polymerization technique. By using the proper molar ratio of APS/aniline monomer and DBSA/aniline monomer, the highest conductivity(7 S/cm) of PANI was obtained. The UV-Vis absorption spectrum of PANI confirmed PANI is emeraldine salt form. PANI/styrene polymers (polystyrene and styrene-butadiene copolymer) blends were prepared by mixing PANI solution with polymers in toluene. These blends exhibited the conductivity of 10$\^$-4/-10$\^$-3/ S/cm at 1 wt. % of PANI content. The mechanical property of conducting blend was decreased and TGA thermograms of conducting blends were similar to that of PANI. It had been checked that the flatness of coating layers of conducting blends decreased with increasing conducting components. It was also found that the morphology of blends was setting closer to that of PANI at higher conducting component contents.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1996.11a
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• pp.187-190
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• 1996

Conducting polymers have band structures similar to those of inorganic semiconductors such as silicon. Several electronic devices have been constructed with conjugated polymers, mainly Schottky diodes and Metal-Insulator-Semiconductor Field-Effect Transistors (MISFET's). Organic semiconductor has been reported as active materials in MISFET's.$^{1.4}$ In our laboratory, $\alpha$-Sexithiencyl ($\alpha$-6T) has been synthesized and purified by sublimation method. In this study, thin films of $\alpha$-Sexithienyl were prepared on various substrates in ultra-high vacuum chamber by vacuum evaporation method, so called OMBD(Organic Molocular Beam Deposition).$^{7.9}$ The $\alpha$-Sexithienyl thin films were deposited with various deposition conditions. The crystalline structure, and molecular orientation of these films have being studied by using UV/Vis. spectroscopy and X-Ray Diffractometry.

• Korean Journal of Veterinary Service
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• v.16 no.1
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• pp.11-19
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• 1993

This experiment was carried out to detect the residues of sulfonamides in raw milk. Raw milks which does not contain sulfonamides was collected from one of the farm and fortified with 5 sulfonamides (sulfamerazine, sulfamethazine, sulfamonomethoxine, sulfadimethoxine, sulfaqinoxaline). The sulfonamides in the fortified sample were extracted and detected by High Performance Liquid Chromatography. UV /vis detector was used in this experiment. The results obtained were summarized as follows : 1. Chloroform was good as a extracting solution. 2. 15.5% methanol in PDP as a mobile phase solution was best detective condition for SMR, SMT, SMM. But for SDM and SQN the best condition was 23% methanol. 3. The detectable limits of SMR, SMT, SMM were 2ppb. but SDM and SQN were 20ppb because of delayed retention time and relatively low recovery rate. 4. The peaks of SMR, SMT, SMM and SDM were erected at baseline and the apexes were sharp but SQN was round shape.

• Horticultural Science & Technology
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• v.32 no.1
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• pp.105-114
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• 2014

We established a high throughput screening system of African yam tuber lines which contain high contents of total carotenoids, flavonoids, and phenolic compounds using ultraviolet-visible (UV-VIS) spectroscopy and Fourier transform infrared (FT-IR) spectroscopy in combination with multivariate analysis. The total carotenoids contents from 62 African yam tubers varied from 0.01 to $0.91{\mu}g{\cdot}g^{-1}$ dry weight (wt). The total flavonoids and phenolic compounds also varied from 12.9 to $229{\mu}g{\cdot}g^{-1}$ and from 0.29 to $5.2mg{\cdot}g^{-1}$dry wt. FT-IR spectra confirmed typical spectral differences between the frequency regions of 1,700-1,500, 1,500-1,300 and $1,100-950cm^{-1}$, respectively. These spectral regions were reflecting the quantitative and qualitative variations of amide I, II from amino acids and proteins ($1,700-1,500cm^{-1}$), phosphodiester groups from nucleic acid and phospholipid ($1,500-1,300cm^{-1}$) and carbohydrate compounds ($1,100-950cm^{-1}$). Principal component analysis (PCA) and subsequent partial least square-discriminant analysis (PLS-DA) were able to discriminate the 62 African yam tuber lines into three separate clusters corresponding to their taxonomic relationship. The quantitative prediction modeling of total carotenoids, flavonoids, and phenolic compounds from African yam tuber lines were established using partial least square regression algorithm from FT-IR spectra. The regression coefficients ($R^2$) between predicted values and estimated values of total carotenoids, flavonoids and phenolic compounds were 0.83, 0.86, and 0.72, respectively. These results showed that quantitative predictions of total carotenoids, flavonoids, and phenolic compounds were possible from FT-IR spectra of African yam tuber lines with higher accuracy. Therefore we suggested that quantitative prediction system established in this study could be applied as a rapid selection tool for high yielding African yam lines.

• Korean Journal of Food Science and Technology
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• v.34 no.5
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• pp.762-769
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• 2002

As a preliminary test for defining intact yellow croaker pigment, the pigment was analyzed by column chromatography and UV-vis spectrophotometry. All maximum absorbance wavelengths commonly showed three maximum absorbance ranges, similar to those of carotenoid, suggesting that the tested pigment may be carotenoid. We detected total six peak RT values in the chromatogram through PDA-HPLC under gradient mode (behavior A at 10% for initial 2 min and changed to behavior B for 60 min). Most pigments were detected at the peak with 3.27 RT value. Because seven peaks were detected under gradient mode and three under isocratic mode [methanol : methylene chloride (90 : 10, v/v)], gradient mode was determined to be more appropriate for quantitative analysis. By the comparison test of RT values among yellow pigment in croakers and reference pigments, such as zeaxanthine, ${\beta}-cryptoxanthine$, ${\beta}-carotene$, and astaxanthin, only ${\beta}-cryptoxanthine$ was detected in the white croaker, whereas such pigment of yellow croaker having RT value of 31.02 was not detected. Therefore, RT value was found to be applicable for detecting adulterated croaker.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.40 no.2
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• pp.121-131
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• 2014

Due to the high UV light scattering effect of Zinc oxide (ZnO), it is frequently used in sunscreen skincare products. Recently ZnO coated with silica has been used in cosmetics to improve UV protection, texture, decreased photocatalytic activity, dispersibility and stability of the skin care product. In this study, we developed a ZnO composite powder coated with silica for the future application to skincare products to block UV rays that could cause photoaging. To improve consumer's satisfaction rating, we used ZnO microparticles which are widely used in the cosmetics industry. The silica was coated using hydrothermal method with sodium silicate and acid hydrolysis. UV protection of the composite powder was analyzed by UV-Vis and in-vitro test and the advantages for practical use of this powder as a skincare product were determined.

• Applied Chemistry for Engineering
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• v.26 no.3
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• pp.356-361
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• 2015

$Cd_{0.5}Zn_{0.5}S/ZnO$ composite photocatalysts were synthesized using the precipitation method and characterized by XRD, UV-vis DRS, PL and FE-SEM. Photocatalytic activities of the materials were evaluated by measuring the degradation of rhodamine B under visible light irradiation. Contrary to ZnO, $Cd_{0.5}Zn_{0.5}S/ZnO$ materials absorb visible light as well as UV and their absorption intensities in visible region increased with increasing the $Cd_{0.5}Zn_{0.5}S$ amount. The increment in the $Cd_{0.5}Zn_{0.5}S$ content in $Cd_{0.5}Zn_{0.5}S/ZnO$ also leads to reducing the particle size and consequently increasing the specific surface area. $Cd_{0.5}Zn_{0.5}S/ZnO$ materials with the larger $Cd_{0.5}Zn_{0.5}S$ content showed the higher activity in the photocatalytic degradation of rhodamine B under visible light irradiation. Therefore, the heterojunction effect between $Cd_{0.5}Zn_{0.5}S$ and ZnO as well as the adsorption capacity seems to give important contributions to the photocatalytic activity of the $Cd_{0.5}Zn_{0.5}S/ZnO$.

• Journal of the Korean Applied Science and Technology
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• v.35 no.3
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• pp.595-605
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• 2018

In recent years, researches on organic-inorganic coating films have conducted a nanocomposite system composed of organic resin matrices having excellent flexibility and chemical stability and inorganic materials having excellent mechanical properties. The o-phenylphenoxyethyl acrylate (OPPEA) used as the acrylate monomer has a high refractive index of 1.58, and the bisphenol A ethoxylate diacrylate (BAEDA) has a low refractive index but improves the chemical stability of the organic resin. In addition, zirconia used as an inorganic material exhibits excellent durability and optical properties. In this study, the BAEDA contents in acrylate monomer were controlled to produce a film with suitable optical transparency. And optimum conditions were established by comparing the changes in surface properties of PET films detected with pencil hardness tester, Abbe's refractometer, and UV-vis spectrophotometer. The hydrophobicity and the dispersibility of zirconia in acrylate monomer were much improved after modification with ${\gamma}$-methacryloxypropyltrimethoxysilane (MPS), which is a silane coupling agent. And the existence of ester C=O bond peak at $1716cm^{-1}$ introduced by MPS through FT-IR ATR spectrophotometer confirmed the completion of surface modification of zirconia with MPS. In addition, the presence of silicon atom on the surface modified zirconia was also proved using X-ray fluorescence spectrometer. When the photocurable hybrid coating was prepared by introducing chemically modified zirconia into acrylate monomer, the refractive index of this coated PET film was improved by 1.2%, compared to the only acrylate coated PET film. The homogeneous distribution of zirconia in acrylate coating layer on PET film was also identified through SEM/EDS mapping analysis technique.