• 접착 및 계면
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• 제13권4호
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• pp.188-192
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• 2012

in-situ 무유화 유화중합 및 후속 CdS 코팅 공정으로 이루어진 방법을 이용하여 CdS로 코팅된 PMMA 나노입자를 제조하고 그 특성을 분석하였다. 합성된 CdS/PMMA 나노입자의 크기는 201.7 nm 였으며, TGA 및 원소 분석 결과 10.37 wt%의 CdS를 함유하고 있었다. PMMA 입자 표면에 코팅된 CdS 나노결정의 크기는 3.55 nm였으며 주로 (111) 결정면으로 성장되었다. UV-vis 분석 결과 blue-shifting 현상이 관찰되었으며, 이는 CdS/PMMA 하이브리드 입자상태에서의 CdS는 벌크 상태의 CdS가 갖는 2.41 eV의 밴드갭 에너지보다 큰 2.70 eV를 갖기 때문에 발생하는 양자구속효과에 의하여 기인하였다.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2011년도 춘계학술대회 초록집
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• pp.106.1-106.1
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• 2011

The Cu(In,Ga)Se2 (CIGS) thin film solar cells have been achieved until almost 20% efficiency by NREL. These solar cells include chemically deposited CdS as buffer layer between CIGS absorber layer and ZnO window layer. Although CIGS solar cells with CdS buffer layer show excellent performance, the short wavelength response of CIGS solar cell is limited by narrow CdS band gap of about 2.42 eV. Taking into consideration the environmental aspect, the toxic Cd element should be replaced by a different material. Among Cd-free candidate materials, the CIGS thin film solar cells with ZnS buffer layer seem to be promising with 17.2%(module by showa shell K.K.), 18.6%(small area by NREL). However, ZnS/CIGS solar cells still show lower performance than CdS/CIGS solar cells. There are several reported reasons to reduce the efficiency of ZnS/CIGS solar cells. Nakada reported ZnS thin film had many defects such as stacking faults, pin-holes, so that crytallinity of ZnS thin film is poor, compared to CdS thin film. Additionally, it was known that the hetero-interface between ZnS and CIGS layer made unfavorable band alignment. The unfavorable band alignment hinders electron transport at the heteo-interface. In this study, we focused on growing defect-free ZnS thin film and for favorable band alignment of ZnS/CIGS, bandgap of ZnS and CIGS, valece band structure of ZnS/CIGS were modified. Finally, we verified the photovoltaic properties of ZnS/CIGS solar cells.

• 한국진공학회지
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• 제1권3호
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• pp.353-359
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• 1992

본 연구에서는 HWE 방법에 의하여 GaAs(100) 기판위에 입방정의 단결정 박막을 성장하였다. 성장된 CdS 단결정 박막의 결정구조와 방향을 ECP(electron channeling pattern)로 결정하였다. CdS 박막의 (400)면이 기판과 평행하게 성장됨을 알았다. CdS 박 막의 photoluminescence를 20K에서 측정하였는데, free exception, bound exception 및 donor-acceptor pair에 의한 발광이 관측되었다.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2009년도 제38회 동계학술대회 초록집
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• pp.57-57
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• 2010

Self assembled $Zn_{x-1}Cd_xS$ nanowires, synthesized on a Indium tin oxide coated glass substrate with low composition of Cd as x=0.09, were fabricated non-precursor via a co-evaporation method using of solid sources of CdS and ZnS. We studies that ZnCdS nanowires are dislocation-free and the single crystalline hexagonal wurtzite structure showed by transmission electron microscopy and selected area electron diffraction pattern. Cathode luminescence spectra showed an near band edge peak at 383nm originated from nanowires at 80K and 300K. Core level spectra of the Cd 3d, Zn 2p and S 2p in the ZnCdS nanorods were obtained by x-ray photoelectron spectroscopy. Prepared ZnCdS nanorods showed different shape with increase of substrate temperature at the growth.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2006년도 춘계학술대회
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• pp.152-153
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• 2006

The new approach to buffer layer design for CIGS solar cells that permitted to reduce the buffer absorption losses in the short wavelength range and to overcome the disadvantages inherent to Cd-free CIGS solar cells was proposed. A chemical bath deposition method has been used to produce a high duality buffer layer that comprises thin film of CdS and Zn-based film. The double layer was grown on either ITO or CIGS substrates and its morphological, structural and optical properties were characterized. The Zn-based film was described as the ternary compound $ZnS_x(OH)_y$. The composition of the $ZnS_x(OH)_y$ layer was not uniform throughout its thickness. $ZnS_x(OH)_y$/CdS/substrate region was a highly intermixed region with gradually changing composition. The short wavelength cut-off of double layer was shifted to shorter wavelength (400nm) compared to that (520 nm) for the standard CdS by optimization of the double buffer design. The results show the way to improve the light energy collection efficiency of the nearly cadmium-free CIGS-based solar cells.

• 공업화학
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• 제25권6호
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• pp.577-580
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• 2014

CIGS 태양 전지용 cadmium (Cd)-free $In(OH)_xS_y$ 버퍼층을 화학적 용액성장법을 이용해서 형성시켰고 최적 반응시간을 파악하였다. 투과율 측정과 함께 이온집적빔 시스템으로 직접 박막을 관찰해서 박막성장 조건을 최적화 하였으며 X선 회절분석법과 X선 광전자 분광법, 주사현미경을 이용해서 박막의 특성을 파악하였다. 그 결과 $In(OH)_xS_y$ 버퍼층의 증착을 위한 최적 반응 시간은 온도 섭씨 $70^{\circ}$의 조건에서 20 min임을 확인하였으며, 이때의 버퍼층의 두께는 57 nm 가량이었고 밴드갭 에너지는 2.7 eV를 나타내었다. 아울러 molybdenum (Mo)층과 CIGS층 위에서 $In(OH)_xS_y$ 버퍼층을 형성시키는 경우에 XPS 피크의 차이는 볼 수 없었다.

• The Korean Journal of Physiology and Pharmacology
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• 제6권1호
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• pp.21-26
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• 2002

Effects of cadmium (Cd) intoxication on renal endosomal accumulation of organic cations $(OC^+)$ were studied in rats using $^{14}C-tetraethylammnium$ (TEA) as a substrate. Cd intoxication was induced by s.c. injections of 2 mg Cd/kg/day for $2{\sim}3$ weeks. Renal cortical endosomes were isolated and the endosomal acidification (acridine orange fluorescence change) and TEA uptake (Millipore filtration technique) were assessed. The TEA uptake was an uphill transport mediated by $H^+/OC^+$ antiporter driven by the pH gradient established by $H^+-ATPase.$ In endosomes of Cd-intoxicated rats, the ATP-dependent TEA uptake was markedly attenuated due to inhibition of endosomal acidification as well as $H^+/TEA$ antiport. In kinetic analysis of $H^+/TEA$ antiport, Vmax was reduced and Km was increased in the Cd group. Inhibition of $H^+/TEA$ antiport was also observed in normal endosomes directly exposed to free Cd (but not Cd-metallothionein complex, CdMt) in vitro. These data suggest that during chronic Cd exposure, free Cd ions liberated by lysosomal degradation of CdMt in proximal tubule cells may impair the endosomal accumulation of $OC^+$ by directly inhibiting the $H^+/OC^+$ antiporter activity and indirectly by reducing the intravesicular acidification, the driving force for $H^+/OC^+$ exchange.

• 대한두경부종양학회지
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• 제21권1호
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• pp.48-52
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• 2005

Objectives: Castleman's disease(CD) is a lymphoproliferative disorder of unknown etiology. To elucidate the clinicopathologic characteristics of CD, we retrospectively reviewed our experience. Methods: Fifteen patients with CD of the neck and mediastinum were identified. Patients were divided into two groups: group I had an unicentric CD and group II had multicentric CD. The histology of CD was divided into 3 subtypes: hyaline-vascular(HV), plasma cell(PC), and mixed. Results: The study included 12 cases of group I, 3 cases of group II in the clinical aspect and 10 cases with HV, 3 cases with PC, 2 cases with mixed type in the histologic aspect. Of group I patients who underwent complete surgical excision, all are currently free of disease. The clinical course of group II patients was variable. Of two patients with multicentric plasma cell CD who were treated, one remain free from disease and the other had a local recurrence in the neck. One patient with multicentric mixed CD died of disease after 30 months of presentation. Conclusion: Surgical resection is recommend for patients with the unicentric CD, regardless of histologic subtype. Patients with multicentric disease do not benefit from surgical resection and should be candidates for multimodality therapy.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2011년도 제41회 하계 정기 학술대회 초록집
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• pp.218-218
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• 2011

The CIGS Solar Cells have the highest conversion efficiency in the film-type solar cells. They consist of p-type CuInSe2 film and n-type ZnO film. The CdS films are used as buffer layer in the CIGS solar cells since remarkable difference in the lattice constant and energy band gap of two films. The CdS films are toxic and make harmful circumstances. The CdS films deposition process need wet process. In this works, we design and make the hitter and lamp reflection part in the sputtering system for the ZnS films deposition as buffer layer, not using wet process. Film thickness, SEM, and AFM are measured for the uniformity valuation of the ZnS films. We conclude the optimum deposition temperature for the films uniformity less than 1.6%. The ZnS films deposited by the sputtering system are more dense and uniform than the CdS films deposited by the Chemical Bath Deposition Method(CBD) for the CIGS Solar Cells.

• 한국태양에너지학회:학술대회논문집
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• 한국태양에너지학회 2012년도 춘계학술발표대회 논문집
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• pp.146-148
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• 2012

In our study, we have focused on optimizing good quality of ZnS buffer layer by chemical bath deposition (CBD) from a bath containing $ZnSO_4$, Thiourea and Ammonia in aqueous solution onto CIGS solar cells. The influence of deposition parameter such as pH, deposition temperature, stirring speed played a very important role on transmission, homogeneity, crystalline of ZnS buffer layer. The transmission spectrum showed a good transmission characteristic above 80% invisible spectral region. CIGS thin flim solar cell with ZnS buffer layer has been realized with the efficiency of 14.2%.