• Korean Journal of Materials Research
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• v.21 no.8
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• pp.432-438
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• 2011

In this study, chemical bath deposited (CBD) indium sulfide buffer layers were investigated as a possible substitution for the cadmium sulfide buffer layer in CIGS thin film solar cells. The performance of the $In_2S_3$/CIGS solar cell dramatically improved when the films were annealed at $300^{\circ}C$ in inert gas after the buffer layer was grown on the CIGS film. The thickness of the indium sulfide buffer layer was 80 nm, but decreased to 60 nm after annealing. From the X-ray photoelectron spectroscopy it was found that the chemical composition of the layer changed to indium oxide and indium sulfide from the as-deposited indium hydroxide and sulfate states. Furthermore, the overall atomic concentration of the oxygen in the buffer layer decreased because deoxidation occurred during annealing. In addition, an In-thin layer was inserted between the indium sulfide buffer and CIGS in order to modify the $In_2S_3$/CIGS interface. The $In_2S_3$/CIGS solar cell with the In interlayer showed improved photovoltaic properties in the $J_{sc}$ and FF values. Furthermore, the $In_2S_3$/CIGS solar cells showed higher quantum efficiency in the short wavelength region. However, the quantum efficiency in the long wavelength region was still poor due to the thick buffer layer.

• Bulletin of the Korean Chemical Society
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• v.23 no.11
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• pp.1519-1523
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• 2002

A procedure for preparing semiconductor/metal nanowire arrays is described, based on a template method which entails electrochemical deposition into nanometer-wide parallel pores of anodic aluminum oxide films on aluminum. Aligned CdS/Co heterostructured nanowires have been prepared by ac electrodeposition in the anodic aluminum oxide templates. By varying the preparation conditions, a variety of CdS/Co nanowire arrays were fabricated, whose dimensional properties could be adjusted.

• Journal of the Korea Society of Computer and Information
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• v.18 no.9
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• pp.33-41
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• 2013

In this paper, a photovoltaic switch is suggested that is operated by solar module, a substitute for CdS(Cadmium Sulfide) of most existing automatic switches and thus is powered by its renewably charged battery, and its usability is investigated through various experiments. At first the characteristics of CdS and the operation principle of the existing automatic switch are investigated, and then the characteristics of solar module are examined. These preparatory research shows the possibility of substitution of solar module instead of CdS in light activated switch. Secondly the suggested photovoltaic switch's circuit is designed, implemented and then its experimental comparison data shows the possibility for the replacement of the existing switch to the suggested switch, and furthermore its superiorities.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.7 no.2
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• pp.315-323
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• 1997

The sing1e crystal of cadmium sulfide was grown by vertical sublimation method. The lattice constants of CdS single crystal by extrapolation method are $a_0=4.139\AA$ and $c_0=6.719\AA$, respectively. The $Cu_2$S/CdS solar cell was fabricated using the single crystal of cadmium sulfide and the CuCl solution. The light- to- dark JV cross over effect of the $Cu_2$S/CdS solar cell was measured after annealing for 2 minutes at $250^{\circ}C$ in air atmosphere. The values of Voc, Jsc, Vop, FF, and efficiency are 0.40 volt, $4.2mA/\textrm{cm}^2$, 0.31 volt, $3.8mA/\textrm{cm}^2$, 0.68 and 3.8 %, respectively. The spectral response of the solar cell shows the peaks at 498 nm (2.49 eV) and 585 nm (2.12 eV).

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.14 no.2
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• pp.104-110
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• 2001

Structural, optical and electrical properties of Cd$_{1-x}$ Zn$_{x}$S films deposited by chemical bath deposition(CBD), which is a very attractive method for low-cost and large-area solar cells, are presented. Especially, in order to control more effectively the zinc component of the films, zinc acetate, which was used as the zinc source, was added in the reaction solution after preheating the reaction solution and the pH of the reaction solution decreased with increasing the concentration of zinc acetate. The films prepared after preheating and pH control had larger zinc component and higher optical band gap. The crystal structures of Cd$_{1-x}$ Zn$_{x}$S films was a wurtzite type with a preferential orientation of the (002) plane and the lattice constants of the films changed from the value for CdS to those for ZnS with increasing the mole ratio of the zinc acetate. The minimum lattice mismatch between Cd$_{1-x}$ Zn$_{x}$S and CdTe were 2.7% at the mole ratio of (ZnAc$_2$)/(CdAc$_2$+ZnAc$_2$)=0.4. As the more zinc substituted for Cd in the films, the optical transmittance improved, while the absorption edge shifted toward a shorterwavelength. the photoconductivity of the films was higher than the dark conductivity, while the ratio of those increased with increasing the mole ratio of zinc acetate. acetate.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.11a
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• pp.105-106
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• 2008

Structural, optical and electrical properties of CdS films deposited by chemical bath deposition (CBD), which are a very attractive method for low-cost and large-area solar cells, are presented. Cadmium sulfide (CdS) is II-VI semiconductor with a wide band gap of approximately 2.42 eV. CdS films have a great application potential such as solar cell, optical detector and optoelectronics device. In this paper, effects of Rapid Thermal Process (RTP) on the properties of CdS films were investigated. The CdS films were prepared on a glass by chemical bath deposition (CBD) and subsequently annealed at standard temperature $(400^{\circ}C)$ and treatment time (10 min) in various atmospheres (air, vacuum and $N_2$). The CdS films treated RTP in $N_2$ for to min were showed larger grain size and higher carrier density than the other samples.

• Transactions on Electrical and Electronic Materials
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• v.11 no.4
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• pp.170-173
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• 2010

Nanocrystalline cadmium sulfide (CdS) thin films were prepared using chemical bath deposition in a solution bath containing $CdSO_4$, $SC(NH_2)_2$, and $NH_4OH$. The CdS thin films were investigated using X-ray diffraction (XRD), photoluminescence (PL), and Fourier transform infrared spectroscopy (FTIR). The as-deposited CdS thin film prepared at $80^{\circ}C$ for 60 min had a cubic phase with homogeneous and small grains. In the PL spectrum of the 2,900 A-thick CdS thin film, the broad red band around 1.7 eV and the broad high-energy band around 2.7 eV are attributed to the S vacancy and the band-to-band transition, respectively. As the deposition time increases to over 90 min, the PL intensity from the band-to-band transition significantly increases. The temperature dependence of the PL intensity for the CdS thin films was studied from 16 to 300 K. The $E_A$ and $E_B$ activation energies are obtained by fitting the temperature dependence of the PL intensity. The $E_A$ and $E_B$ are caused by the deep trap and shallow surface traps, respectively. From the FTIR analysis of the CdS thin films, a broad absorption band of the OH stretching vibration in the range $3,000-3,600\;cm^{-1}$ and the peak of the CN stretching vibration at $2,000\;cm^{-1}$ were found.

• Journal of Korean Society of Water and Wastewater
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• v.13 no.2
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• pp.47-54
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• 1999

SRB(Sulfate Reducing Bacteria) converts sulfate into sulfide using an organic carbon source as the electron donor. The sulfide formed precipitates the various metals present in the AMD (Acid Mine Drainage). This study is the fundamental research on heavy metal removal from AMD using SRB. Two completely mixed anaerobic reactors were operated for cultivation of SRB at the temperature of $30^{\circ}C$ and anaerobic batch reactors were used to evaluate the effects of carbon source, COD/sulfate($SO_4^=$) ratio and alkalinity on sulfate reduction rate and heavy metal removal efficiency. AMD used in this study was characterized by low pH 3.0 and 1000mg/l of sulfate and dissolved high concentration of heavy metals such as iron, cadmium, copper, zinc and lead. It was found that glucose was an organic carbon source better than acetate as the electron donor of SRB for sulfate reduction in AMD. Amount of sulfate reduction maximized at the COD(glucose)/sulfate ratio of 0.5 in the influent and then removal efficiencies of heavy metals were 97.5% of Cu, 100% of Pb, 100% of Cr, 49% of Mn, 98% of Zn, 100% Cd and 92.4% of Fe. Although sulfate reduction results in an increase in the alkalinity of the reactor, alkalinity of 1000mg/1 (as $CaCo_3$) should be should be added continuously to the anaerobic reactor in order to remove heavy metals from AMD.

• Current Photovoltaic Research
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• v.2 no.4
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• pp.152-156
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• 2014

We report hybrid solar cells fabricated with polymer/fullerene bulk heterojunction layers that contain inorganic nanocrystals synthesized by in-situ reaction in the presence of polymer chains. The inorganic (cadmium sulfide) nanocrystal ($CdS_{NC}$) was generated by the reaction of cadmium acetate and sulfur by varying the reaction time up to 30 min. The synthesized $CdS_{NC}$ showed a rectangular flake shape, while the size of $CdS_{NC}$ reached ca. 150 nm when the reaction time was 10 min. The performance of hybrid solar cells with $CdS_{NC}$ synthesized for 10 min was better than that of a control device, whereas poor performances were measured for other hybrid solar cells with $CdS_{NC}$ synthesized for more than 10 min.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1992.05a
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• pp.46-49
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• 1992

Cadmium sulfide thin films were deposited on glass substrate by Chemical Mist Deposition from solutions containing equimolar (0.1M) cadmium chloride and thiourea [(NH$_2$)$_2$CS] at a mist velocity of 1.6m/sec. Substrate temperatures were ranged between 200$^{\circ}C$ and 400$^{\circ}C$. The microstructure and semiconducting property of the films were investigated using SEM, X-ray diffraction, UV transmittance measurement and four point probe method. All the films have hexagonal structure and diffraction patterns indicate that the intensity of (112) and (101) reflections increase with increasing substrate temperature, whereas (002) reflection substrate temperature, whereas(002) reflection decrease for substrate temperatures between 250$^{\circ}C$ and 350$^{\circ}C$. The films prepared at lower temperature have a significant number of pinholes due probably to entrapped gaseous reaction. Optical transmittance of the films deposited at 350$^{\circ}C$ was about 75%. Optical bandgap of the films were 2.43eV regardless of substrate temperature. The dark resistivity of the films decreased with increasing substrate temperature up to 300$^{\circ}C$ and increased with further increasing substrate temperature. The films were photosensitive and had dark-to-light resistivity ratios of about 10 at room temperature for a white-light photoexcitation intensity of 50mw/$\textrm{cm}^2$.