• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2005.11a
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• pp.63-64
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• 2005

CdS thin films were fabricated by rf magnetron sputter technique, and annealed in tube furnace using vacuum evaporated $CdCl_2$ layer, In addition, effects of the thickness of $CdCl_2$ layer and the annealing temperature on structural and optical properties of CdS films were investigated. The heat treatment process was carried out by heating the sample in air at $350-500^{\circ}C$ for 20 minute.

• Korean Journal of Materials Research
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• v.21 no.9
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• pp.497-501
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• 2011

The CdS thin film used as a window layer in the CdTe thin film solar cell transports photo-generated electrons to the front contact and forms a p-n junction with the CdTe layer. This is why the electrical, optical, and surface properties of the CdS thin film influence the efficiency of the CdTe thin film solar cell. When CdTe thin film solar cells are fabricated, a heat treatment is done to improve the qualities of the CdS thin films. Of the many types of heat treatments, the $CdCl_2$ heat treatment is most widely used because the grain size in CdS thin films increases and interdiffusion between the CdS and the CdTe layer is prevented by the heat treatment. To investigate the changes in the electrical, optical, and surface properties and the crystallinity of the CdS thin films due to heat treatment, CdS thin films were deposited on FTO/glass substrates by the rf magnetron sputtering technique, and then a $CdCl_2$ heat treatment was carried out. After the $CdCl_2$ heat treatment, the clustershaped grains in the CdS thin film increased in size and their boundaries became faint. XRD results show that the crystallinity improved and the crystalline size increased from 15 to 42 nm. The resistivity of the CdS single layer decreased from 3.87 to 0.26 ${\Omega}cm$, and the transmittance in the visible region increased from 64% to 74%.

• Proceedings of the Materials Research Society of Korea Conference
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• 1997.10a
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• pp.121-121
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• 1997

• Proceedings of the KIEE Conference
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• 1996.07c
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• pp.1418-1420
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• 1996

In this paper, structural properties of CdTe thin films and photovoltaic properties of thin film CdS/CdTe solar ceIl prepared by thermal vacuum evaporation were studied. Structural variation with $CdCl_2/heat$ treatment are assessed using x-ray diffraction and scanning electron microscopy. The crystal structure of CdTe films was zincblend type with preferential orientation of the (111) plane parallel to the substrate. The $CdCl_2$ treatment appears to increase the grain size of polycrystalline CdTe thin film. It was found that CdS/CdTe solar cell characteristics were improved by the heat treatment with $CdCl_2$. The conversion efficiency, however, decreased when heat treatment temperature was too high.

• Transactions of the Korean hydrogen and new energy society
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• v.13 no.3
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• pp.224-232
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• 2002

CdS-$TiO_2$ nano-composite sol was prepared by the sol-gel method in organic solvents at room temperature and further hydrothermal treatment at various temperatures to control the physical properties of the primary particles. Again, CdS-$TiO_2$ composite particulate films were made by casting CdS-$TiO_2$ sols onto $F:SnO_2$ conducting glass and then heat-treatment at $400^{\circ}C$. Physical properties of these 61ms were further controlled by the surface treatment with $TiCl_4$, aqueous solution. The photo currents and hydrogen production rates measured under the experimental conditions varied according to the $CdS/[CdS+TiO_2]$ mole ratio and the mixed-sol preparation method. For $CdS-TiO_2$ composite sols prepared in IPA, CdS particles were homogeneously surrounded by $TiO_2$ particles. Also, the surface treatment with $TiCl_4$ aqueous solution caused a considerable improvement in the photocatalytic activity, probably as a result of close contacts between the primary particles by the etching effect of $TiCl_4$. It was found that the photoelectrochemical performance of these particulate films could be effectively enhanced by this approach.

• Transactions of the Korean hydrogen and new energy society
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• v.13 no.1
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• pp.34-41
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• 2002

CdS and $TiO_2$ nanoparticles were made by the precipitation method and sol-gel method, respectively, and they were mixed mechanically and then treated with the hydrothermal processing. CdS-$TiO_2$ composite particulate films were thus prepared by casting CdS-$TiO_2$ mixed sol onto $SnO_2$ conducting glass and a subsequent heat-treatment at $400^{\circ}C$. Again, the physico-chemical and photoelectrochemical properties of these films were controlled by the surface treatment with $TiCl_4$ aqueous solution. The photocurrents and the hydrogen production rates measured under the present experimental conditions varied in the range of $3.5{\sim}4.5mA/cm^2$ and $0.3{\sim}1.8cc/cm^2$-hr, respectively, and showed the maximum values at the $CdS/[CdS+TiO_2]$ mole ratio of 0.2. Also, the surface treatment with $TiCl_4$ aqueous solution caused a considerable improvement in the photocatalytic activity, Probably as a result of close contacts between the primary particles by the etching effect of $TiCl_4$ It was found that the photoelectrochemical performance of these particulate films could be effectively enhanced by this approach.

• Journal of Environmental Health Sciences
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• v.22 no.4
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• pp.91-101
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• 1996

Exposure indices are important tools which enable scientists to reliably predict and detect exposures to xenobiotics and resultant cell injury. Since the de novo synthesis of stress proteins can be detected early after exposure to some agents, analysis of toxicant-induced changes in gene expression, i.e. alterations in patterns of protein synthesis, may be useful to develop as biomarkers of exposure and toxicity. The acute and chronic effects of cadmium(Cd, $CdCl_2$ 20 mg/kg) on Wistar male rats were evaluated concerning cadmium contents, tissues enzyme activity, HSP expression. The results of the study were as follows: 1. Less cadmium was absorbed through the digestive tracts, but the ratio of contents in renal to hepatic cadmium was higher at 8 weeks after treatment. 2. ALT(alanine aminotransferase), AST(aspartate aminotransferase), glucose, BUN(blood urea nitrogen), creatinine, the key indices of the clinical changes in hepatic and renal function were significantly changed by the cadmium treatment after 1 week in liver, after 4 weeks in kidney. 3. Enhanced synthesis of 70 KDa relative molecular mass proteins were detected in 2 hours after cadmium exposure, with maximum activity occurring at 8~48 hours. Induction of $HSP_{70}$ was evident at proximal tubules and glomeruli in kidney. Testicular cells produced enough HSP to be detected normally. From the above results, it could be concluded that $HSP_{70}$ induction by the cadmium treatment was a rapid reaction to indicate the exposure of xenobiotics.

• Journal of Food Hygiene and Safety
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• v.13 no.2
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• pp.171-187
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• 1998

Garlic occupies a special position among the many foods of vegetable origin because it is the sole food for Koreans during the their lives. And vitamin A has been ingested by forms of food or additives. Cadmium has been described as one of the most dangerous trace elements in the food and environment of man and livestocks. Since the de novo synthesis of stress proteins can be detected early after exposure to some agents, analysis of cadmium-induced changes in gene expression , ie. alterations in patterns of protein synthesis, may be useful to develop as biomarkers of exposure and damage for food hygiene. He acute and chronic combine effects of cadmium (Cd, CdCl2 20mg/kg), garlic oil(Dds: diallyl disulfide 50mg/kg, 3 times a week) and vitamin A(Ra: retinol acetate 50,000 IU/kg, 3 times a week) on Wistar male rats were evaluated concerning cadmium contents, tissues enzyme activity, HSP expression histopathological and electron microscopical examinations. The results of the study are as follows ; 1. Less cadmium was absorbed through the digestive tracts, but the ratio of contents in tissue were not changed by the simultaneous adminstration of diallyl disufide or retinol acetate. 2. ALT(alanine aminotransferase) , AST(aspartate aminotransferase), glucose, BUN (blood urea nitrogen), creatinine, the key indices of the clinical changes in hepatic and renal function were significantly hanged by the cadmium treatment after 1 week in liver, after 4 weeks in kidney. 3. Histopathological changes in cadmium treated rats were appeared at 8 weeks age treatment in kidneys. Homogenous eosinophilic material was accumulated in cortical and collecting tubular lumens at 16 weeks. Degenerated or necrotized tubular cells were observed in cortex and medulla. Degenerated seminiferous tubules and homogeneous eosinophilic material was seen in interstitial tissue of rat treated with cadmium for 16 weeks. Calcium deposits were seen in degenerated seminiferous tubules and the tubules showed severe calcification of rat treated with cadmium for 16 weeks. Electron microscope changes in kidney were observed in rats treated with CdCl2 20 mg/kg. Proximal convoluted tubule cells showed selling of cytoplasm and narrow lumen. Capillary endothelial cells showed cytoplasmic vacuoles and swelling. Degenerated epithelial cells were accumulated in tubular lumen of kidney. 4. Enhanced synthesis of 70 KDa relateve molecular mass proteins were detected in 2 hours after cadmium, exposure, with maximum activity occurring at 8~48 hours. Induction of HSP 70 was evident at proximal tubules and glomeruli in kidney. Testicular cells produced enough HSP to be detected normally. From the above results, it could be concluded that HSP70 induction by the cadmium treatment was a rapid reaction to indicated the exposure of xenobiotics, and retinol acetate reduced the cadmium induced nephrotoxicity.