• Journal of the Korean Geosynthetics Society
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• v.11 no.1
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• pp.1-9
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• 2012

This paper describes the batch test results for application of CFW(Carbonized Foods Waste), which was produced by the process of recycling waste, in PRB system. It analyzed characteristics for individual adsorption and competitive adsorption of Cu and Zn in heavy metals. In individual adsorption, the Langmuir and Freundlich models are used to predict adsorption equilibrium. The adsorption equilibrium corresponded to the Langmuir's and the maximum adsorption amount of Cu was greater than Zn's. The removal of heavy metal is predicted that Zn was faster than Cu. The reaction rate of Zn based on Pseudo-first-order and Pseudo-second-order was faster than Cu's, and the result of competitive adsorption test confirmed that the adsorption amount of Zn is reduced under similar condition for competitive adsorption rate of Cu and Zn. When Zn solution is mixed in Cu, Cu is adsorbed 86% on CFW. However, the adsorption of Zn is 19% on the contrary condition. Therefore, the removal characteristics of separate heavy metal should be considered for efficient treatment of contaminated ground based on complex heavy metal.

• Journal of the Korean Graphic Arts Communication Society
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• v.29 no.1
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• pp.23-33
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• 2011

This experimental focus to characterize luminescence properties related to CNT (Carbon Nano Tube) element dispersedly implanted in ZnS-based phosphor thin film panel fabricated by a screen printing method. More specifically FE-SEM measurements, L-V(Luminescence vs. Voltage) and photo luminescence were carried out to determine an optimum value of CNT concentration and film thickness for the thin film structure of CNT-ZnS:(Cu, Al) by the screen printing method. We confirmed that an optimum value of CNT concentration in the ZnS:(Cu, Al) film panel is about 0.75 wt% resulting that the electric conductivity is 1.6 times higher than that of pure CNT sample and showing that the luminescence intensity is increasing until the optimum concentration. Clearly, CNT is presenting in the luminescence process providing a pathway for the creation of hot electron and a channel for the electron-hole recombination but overly inserted CNT may hinder to produce the hot electron for making an avalanching process. In case of the overly doped CNT 1.0 wt% in the ZnS-based phosphor, the luminescence intensity is decreasing although the electric conductivity is exponentially increasing. Based on these results, we realized that hot electron occurred by the external electric field or exciton arose by the external photon source are reduced dramatically over the critical value of CNT concentration because CNT element provide various isolated residues in the composites of ZnS based phosphor rather than pathway or channel for the D-A(Donnor to Acceptor) pair transition or the radiative recombination of electron-hole.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.11a
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• pp.322-323
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• 2008

Multi layered thin films with ZnS/$Na_3AlF_6$/ZnS were deposited on glass substrate by thermal evaporator precess and simulated by using EMP(Essential Macleod Program). EMP is a comprehensive software package to design and analyse the optical characteristics of multi-layered thin film. ZnS and $Na_3AlF_6$ were selected as a high refractive index and low refractive index material respectively. Additionally Cu was chosen as mid reflective material. Optical properties including color effect were systematically studied. in terms of different optical thickness of low refractive index material. The optical thickness of $Na_3AlF_6$ was changed as 0.25, 0.5, 0.75 and $1.0\lambda$. The film with 0.25, 0.5, 0.75 and $1.0\lambda$. of optical thickness showed mixed color range between bluish green and red purple, yellowish green and bluish green, purple and mixed color range of green and purple respectively.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.14 no.7
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• pp.1647-1652
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• 2010

A CdS film has been used as a window layer in CdTe and Cu(In,Ga)$Se_2$ thin films solar cell. Partial substitution of Zn for Cd increases the photocurrent and the open-circuit voltage by providing a match in the electron affinities of the two materials and the higher band gap. In this paper, CdZnS/CdTe and CdS/CdTe heterojunctions were fabricated and the electrical characteristics were investigated. Current-voltage-temperature measurements showed that the current transport for CdS/CdTe heterojunction was controlled by both tunneling and interface recombination. However, CdZnS/CdTe heterojunction displayed different current transport mechanism with the operating temperature. For above room temperature, the current transport of device was generation/recombination in the depletion region and was the leakage current and/or tunneling in the range below room temperature.

• 한국신재생에너지학회:학술대회논문집
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• 2007.11a
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• pp.270-273
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• 2007

In this report, Indium-free and Indium-reduced thin film materials for solar absorber were studied in order to search alternative materials for thin film solar cell. The films of $Cu_2ZnSnSe_4$ and $Cu_2ZnSnSe_2$ were deposited using mixed binary chalcogenides powders. From the film bulk analysis result, it is observed that Cu concentration is a function of substrate temperature as well as CuSe mole ratio in the target. Under optimized conditions, $Cu_2ZnSnSe_4$ and $Cu_2ZnSnSe_2$ thin films grow with strong (112), (220/204) and (312/116) reflections. Films are found to exhibit a high absorption coefficient of $10^4$ $cm^{-1}$. $Cu_2ZnSnSe_4$ film shows a 1.5 eV band gap. On the other side, an increasing of optical band gap from 1.0 eV to 1.25 eV ($CuInSnSe_2$) is found to be proportional with an increasing of Zn concentration. All films have a p-type semiconductor characteristic with a carrier concentration in the order of $10^{14}$ $cm^{-3}$, a mobility about $10^1$ $cm^{2{\cdot}-1.}S^{-1}$ and a resistivity at the range of $10^2-10^6$ ${\Omega}{\cdot}m$.

• Journal of the Korean Society for Heat Treatment
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• v.36 no.3
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• pp.115-120
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• 2023

ZnO/Cu/ZnO (ZCZ) thin film deposited on the glass substrate with DC and RF magnetron sputtering was rapid thermal annealed (RTA) and then effect of thermal temperature on the opto-electical and transparent heater properties of the films were considered. The visible transmittance and electrical resistivity are depends on the annealing temperature. The electrical resistivity decreased from 1.68 × 10^-3 Ωcm to 1.18 × 10^-3 Ωcm and the films annealed at 400℃ show a higher transmittance of 78.5%. In a heat radiation test, when a bias voltage of 20 V is applied to the ZCZ film annealed at 400℃, its steady state temperature is about 70.7℃. In a repetition test, the steady state temperature is reached within 15s for all of the bias voltages.

• 한국신재생에너지학회:학술대회논문집
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• 2010.06a
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• pp.85.2-85.2
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• 2010

$Cu_2ZnSnSe_4$ (CZTSe) is one of candidate to alternate $Cu(In,Ga)Se_2$ as solar absorber material for solar cell. The expensive elements of In and Ga are replaced by Zn and Sn, respectively to lower the material cost. In this study we fabricated CZTSe thin film by selenization of single precursor layer consisted metallic constituent. Precursor compositions ratio were selected to have Cu-poor and Zn-rich content and prepared by RF magnetron sputtering. Thermal processing was applied to introduce selenium into as-deposited films at temperatures ranging from 350 to 500 for time up to 120 minutes. Single precursor films showed amorphous structure and consist of individual elements of Cu, Zn, and Sn. It was confirmed by XRD analysis that synthesis of CZTSe compound is occurred from lower temperature process, although concurrently additional phases such as binary cooper selenides are also existed. The quality of CZTSe crystal was improved as temperature increased. We also investigated the optical and electrical properties of as-selenized CZTSe as well.

• Korean Journal of Materials Research
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• v.21 no.1
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• pp.67-71
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• 2011

La doped CuO-ZnO-$Al_2O_3$ powders are prepared by sol-gel method with aluminum isopropoxide and primary distilled water as precursor and solvent. In this synthesized process, the obtained metal oxides caused the precursor such as copper (II) nitrate hydrate and zinc (II) nitrate hexahydrate were added. To improve the surface areas of La doped CuO-ZnO-$Al_2O_3$ powder, sorbitan (z)-mono-9-octadecenoate (Span 80) was added. The synthesized powder was calcined at various temperatures. The dopant was found to affect the surface area and particle size of the mixed oxide, in conjunction with the calcined temperature. The structural analysis and textual properties of the synthesized powder were measured with an X-ray Diffractometer (XRD), a Field-Emission Scanning Electron Microscope (FE-SEM), Bruner-Emmett-Teller surface analysis (BET), Thermogravimetry-Differential Thermal analysis (TG/DTA), $^{27}Al$ solid state Nuclear Magnetic Resonance (NMR) and transform infrared microspectroscopy (FT-IR). An increase of surface area with Span 80 was observed on La doped CuO-ZnO-$Al_2O_3$ powders from $25m^2$/g to $41m^2$/g.

• Journal of Environmental Science International
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• v.4 no.5
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• pp.103-103
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• 1995

In the Chinhae Bay, Korea, sedimentation rates and sedimentary record of anthropogenic metal loads were determined by $^{210}Pb$ dating and heavy metal analysis of four sediment cores . The sedimentation rates varied from 0.16g/$cm^2$/yr(3.1mm/yr) at Sta. Ct, located within narrow waterway to 0.24g/$cm^2$/yr(4.8mm/yr) at Sta. Cl, located in Haengam Bay. Maximum contents of Mn, Zn, Cu and Cr were observed at Sta. C2 located near the mouth of Masan Bay, while minimum contents were observed at Sta. CB. Mn/Fe ratios at Sta. C2 and Sta. C4 showed gradually increasing and decreasing downward, respectively, in the upper layer of sediment cores. This suggests that Mn may be diagenetically redistributed in highly reduced environment. At Sta. C2, the concentrations of Zn and Cu began to increase from 1920s by anthropogenic input and have been remarkablely increasing since mid 1960s. At Sta. C3, located near Sungpo, anthropogenic input of these two elements has also slightly increased after 1970s. However, pollution of these two elements was not significant in Haengam Bay(Sta. Cl) and Chiljun watenway(Sta. C4). The pollution of Co, Ni and Cr was not remarkable in all core samples except surface sediment of Sta. C2. The total input of anthropogenic Zn and Cu since 1920s was estimated to be 28∼792 ㎍/cm2 and 0∼168㎍/cm2, respectively. Sta. C2 showed remarkablely higher values relative to other stations: anthropogenic loads of Zn and Cu constituted 27% and 29% of the total sedimentary inventories at the present day, respectively. Fe, Ni, Cr and Co contents showed good correlation(r>0.8) with each other. Anthropogenic Zn and Cu also showed a very good positive correlation(>0.9). However, correlation between these two group of element was quite scattered, indicating different sources and geochemical behaviors.

• Journal of Environmental Science International
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• v.4 no.5
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• pp.489-500
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• 1995

In the Chinhae Bay, Korea, sedimentation rates and sedimentary record of anthropogenic metal loads were determined by $^{210}Pb$ dating and heavy metal analysis of four sediment cores . The sedimentation rates varied from 0.16g/$cm^2$/yr(3.1mm/yr) at Sta. Ct, located within narrow waterway to 0.24g/$cm^2$/yr(4.8mm/yr) at Sta. Cl, located in Haengam Bay. Maximum contents of Mn, Zn, Cu and Cr were observed at Sta. C2 located near the mouth of Masan Bay, while minimum contents were observed at Sta. CB. Mn/Fe ratios at Sta. C2 and Sta. C4 showed gradually increasing and decreasing downward, respectively, in the upper layer of sediment cores. This suggests that Mn may be diagenetically redistributed in highly reduced environment. At Sta. C2, the concentrations of Zn and Cu began to increase from 1920s by anthropogenic input and have been remarkablely increasing since mid 1960s. At Sta. C3, located near Sungpo, anthropogenic input of these two elements has also slightly increased after 1970s. However, pollution of these two elements was not significant in Haengam Bay(Sta. Cl) and Chiljun watenway(Sta. C4). The pollution of Co, Ni and Cr was not remarkable in all core samples except surface sediment of Sta. C2. The total input of anthropogenic Zn and Cu since 1920s was estimated to be 28~792 $\mu\textrm{g}$/cm2 and 0~168$\mu\textrm{g}$/cm2, respectively. Sta. C2 showed remarkablely higher values relative to other stations: anthropogenic loads of Zn and Cu constituted 27% and 29% of the total sedimentary inventories at the present day, respectively. Fe, Ni, Cr and Co contents showed good correlation(r>0.8) with each other. Anthropogenic Zn and Cu also showed a very good positive correlation(>0.9). However, correlation between these two group of element was quite scattered, indicating different sources and geochemical behaviors.