• The Korean Journal of Ceramics
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• v.6 no.1
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• pp.43-46
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• 2000

$H_4Nb_6/O_{17}$/CdS nanocomposites which intercalated CdS particles, less than 0.8nm thickness, in the interlayer of $H_4Nb_6/O_{17}$ were prepared by the successive ion exchange reactions of $H_4Nb_6/O_{17}$ with $Cd^{2+}$ and $C_3H_7NH_3_+$, followed by the reaction with $H_2S$ gas. $H_4Nb_6/O_{17}$/CdS photocatalytically reduced $NO_3$￣ to $NO_2$￣ and $NH_3$in the presence of sacrificial hole acceptor such as methanol under visible light irradiation (wavelength>400nm), although unsupported CdS showed no noticeable photocatalytic activity for $NO_3$￣ reduction. The catalytic activity of $H_4Nb_6/O_{17}$/CdS greatly enhanced with co-doping of Pt particles in the interlayer.

• Proceedings of the KIEE Conference
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• 1998.07d
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• pp.1370-1372
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• 1998

Boron doped CdS films were prepared by CBD(Chemical Bath Deposition) method using boric acid ($B_3HO_3$) as donor dopant source, and their properties were investigated. As-grown CdS films were highly adherent and specularly reflective. Boron doped CdS film which was fabricated under the condition of 0.01 $B_3HO_3/Cd(Ac)_2$ mole ratio, exhibited the lowest resistivity of $2{\Omega}cm$ and the highest optical bandgap of 2.41eV. Also, CdS/CdTe solar cells were fabricated with various doping concentration of CdS films. Using optimized CdS film as the window layer of CdS/CdTe solar cell, the characteristics of the cell were improved. ( $V_{oc}$=610mV, $J_{sc}$=37.5mA/cm, FF=0.4, $\eta$=9.1% )

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.06a
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• pp.81-81
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• 2008

Applications of CdS films in this study are to exhibit a high conductivity when they are exposed at light with visible wavelength and sequentially to show a low conductivity in dark state. For this purpose, CdS films should have a high photosensitivity, still maintaining a high conductivity at a visible light. In this study, CdS films were prepared at room temperature on glass substrates by rf magnetron sputtering. In order to increase the photo-conductivity in visible light, various defect levels should be located within the CdS band gap. In order to nucleate the defect sites within the CdS band gap, CdS films were deposited on glass substrates at room temperature using various $H_2$/(Ar+$H_2$) flow ratios by an rf magnetron sputtering. Through the investigation of the structural and photoconductive properties of CdS films by an addition of hydrogen, the relationship between photo- and dark-resistance in CdS films was investigated in detail. 200-nm-thick CdS films for photoconductive sensor applications were prepared at various $H_2$/(Ar+$H_2$) flow ratios on glass substrates at room temperature by rf magnetron sputtering. Sulfur concentration in CdS films crystallized at room temperature with (002) preferred orientation depends directly on the hydrogen atmosphere and the surface roughness of the films gradually increases with increasing hydrogen atmosphere. Films deposited at 8% of $H_2$/(Ar+$H_2$) exhibit an abrupt decrease of dark- and photo-resistance, showing a low photo-sensitivity ($R_{dark}/R_{photo}$). Onthe other hand, films deposited at a hydrogen atmosphere of 42% exhibit a photo-sensitivity of $5\times10^3$, maintaining a photo-resistance of an approximately $2\times10^4\Omega$/square. The dark- and photo-resistance values of CdS films were related with a composition, surface roughness, and defect sites within the band gap.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.24 no.8
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• pp.616-621
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• 2011

In this paper, CdS thin films, which were widely used window layer of the CdTe and the Cu(In,Ga)$Se_2$ thin film solar cell, were grown by chemical bath deposition, and effects of pH of reaction solution on the structural and optical properties were investigated. For pH<10.5, as the pH of reaction solution was higher, the deposition rate of CdS films was increased by improving ion-by-ion reaction in the substrate surface and the crystallinity of the films was improved. However, when the pH was higher than 10.5, the deposition rate was decreased because of smaller $Cd^{2+}$ ion concentration in the reaction solution. Also, the crystallinity of the films were deteriorated. The CdS films deposited at lower pH showed poor optical transmittance due to adsorbed colloidal particles, while the transmittance was improved for higher pH.

• Proceedings of the KIEE Conference
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• 1997.07d
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• pp.1436-1438
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• 1997

In this paper, CdS thin films, which were widely used window layer of the CdS/CdTe and the CdS/$CuInSe_2$ heterojunction solar cell, were grown by chemical bath deposition, and The properties were investigated in detail. Cadmium acetate and thiourea were used as cadmium and sulfur source, respectively. And Ammonium acetate was used as the buffer solution. Also Ammonia was used for controlling pH concentration. The reaction velocity was increased with increasing reaction temperature and decreasing pH concentration. The crystal structure of CdS films grown with various pH concentration had the hexagonal structure with (002) plane peak. In the range of pH $9{\sim}9.5$, the intensity of the peak was highest, and as increasing pH concentration, decreased the intensity of the peak except pH12.

• Journal of the Korean institute of surface engineering
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• v.29 no.6
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• pp.862-868
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• 1996

Cadmium sulfide is commonly used as the window material for thin film solar cells, and can be prepared by several techniques such as sputtering, spray pyrolysis, close spaced sublimation (CSS), thermal evaporation, solution growth methods, etc. In this study, CdS films were deposited by thermal evaporation, close spaced sublimation, and solution growth methods, respectively, and the effects of the methods on physical properties of polycrystalline CdS deposited on ITO/glass were investigated. Also, the effects of variously prepared CdS thin films on the physical properties of CdTe deposited on the CdS were investigated. The thickness of polycrystalline CdS films was maintained at $0.3\mu\textrm{m}$ except for the solution grown CdS when $0.2\mu\textrm{m}$ thick CdS was deposited. After the deposition, all the samples were annealed at $400^{\circ}C$ or $500^{\circ}C$ in H2 atmosphere. To investigate physical properties of the deposited and annealed CdS thin films, UV-VIS spectro-photometry, X-ray diffractometry (XRD), and Auger electron spectroscopy (AES), and cross sectional transmission electron microscopy(XTEM) were used to analyze grain size, crystal structure, preferred orientation, optical properties, etc. The annealed CdS showed the bandedge transition at 510nm and the optical transmittance high than 80% for all of the variously deposited films. XRD results showed that CdS thin films variously deposited and annealed had the same hexagonal structures, however, showed different preferred orientations. CSS grown CdS had [103] preferred orientation, thermally evaporated CdS had [002], and CdS grown by the solution growth had no preferred orientation. The largest grain size was obtained for the CSS grown CdS while the least grain size was obtained for the solution grown CdS. Some of the physical properties of CdTe deposited on the CdS thin film such as grain size at the junction and grain orientation were affected by the physical properties of CdS thin films.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.48 no.8
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• pp.563-569
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• 1999

Boron doped CdS films were prepared by chemical bath deposition using boric acid$(H_3BO_3)$ as donor dopant source, and their electrical, optical properties were investigated as a function of doping concentration. In addition, effects of boron doping of CdS films on characteristics of CdS/CdTe solar cells were investigated. Boron doping highly decreased the resistivity and slightly increased optical band gap of CdS films. The lowest value of resistivity was $2 \Omega-cm \;at\; H_3BO_3/Cd(Ac)_2$ molar ratio of 0.1. For the molar ratio more than 0.1, however, the resistivity increased because of decreasing carrier concentration and mobility and showed similar value for undoped films. The photovoltaic characteristics of CdS/CdTe solar cells with boron doped CdS film improved due to the decrease of the conduction band-Fermi level energy gap of CdS films and the series resistance of solar cell.

• 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.

• IMMUNE NETWORK
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• v.12 no.3
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• pp.118-125
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• 2012

CD40-CD40L-mediated help from CD4 T cells is essential to induce primary CD8 T cell responses specific to the non-inflammatory cell-based antigen H60. In this study, using H60 as a model antigen, we generated recombinant vaccinia viruses (rVVs) expressing the H60 CD8 epitope and investigated whether CD4 help was required to activate the CD8 T cell response specific to the virally expressed H60. The immune response after infection with rVVs expressing H60 was similar to that after immunization with H60 congenic splenocytes, with a peak frequency of H60-specific CD8 T cells detected in the blood on day 10 post-infection. A CD8 T cell response specific for virally derived H60 was not induced in CD4-depleted mice, but was in CD40-deficient mice. These results provide insights into the characterization of the CD8 T cell response specifically for antigens originating from cellular sources compared to viral sources.

• Journal of the Korean Ceramic Society
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• v.30 no.11
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• pp.897-904
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• 1993

CdS doped SiO2 glass coating films which are good candidates for the nonlinear optical materials were prepared by the Sol-Gel method. TEOS, C2H5OH, H2O and HCl were used as starting materials to obtain SiO2 matrix solutions. Then Cd(NO3)2.2H2O and CS(NH2)2 were dissolved into the SiO2 matrix solutions. Coating was performed several times in order to increase the thickness of coated film by the dip-coating method. Then heat treatments were carried out to control the size of CdS microcrystals doped in SiO2 glass matrix with respect to temperatures and times. CdS-doped SiO2 transparent coating films were successfully obtained. CdS crystals were changed from cubic to hexagonal type about $600^{\circ}C$.