• Journal of the Korean Crystal Growth and Crystal Technology
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• v.5 no.1
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• pp.78-86
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• 1995

Abstract We have investigated the structure and the conductivity of the CdTe films evaporated on the glass substrates by Electron Beam Evaporator (EBE) technique. The structure is observed to be polycrystalline whose phase is mainly hexagonal phase with some cubic phase. Dark electric conductivity is of the order of $1-^{-8} {\Omega}^{-1} cm^{-1}$ and slightly increased by annealing for an hour at $300^{\circ}C$. Activation energy calculated from the electrical conductivity which varies with increasing temperature is 1.446 eV in the case of room temperature substrates. The values of optical band gap are 1.52 eV in direct transition whereas 1.44 eV in indirect. The photoconductivity of the films is of the order of $1-^{-8} {\Omega}^{-1} cm^{-1}$ and the peak energy is about 600 nm in the room temperature. The photoconductivity starts to increase at 850 nm, which is close to 1.446 eV, the activation energy of CdTe polycrystal films.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.5 no.1
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• pp.67-77
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• 1995

Abstract The principal factor affecting the increased penetration of photovoltaics into the marketplace is cost. For traditional crystalline silicon modules, half of the cost is that of the silicon wafers. As a result much effort has centered on reducing this cost by the use of thin film technologies. Substantial technical progress has been made towards improving the efficiencies of polycrystalline thin film solar cells to reduce the production costs. Progress in semiconductor deposition techniques has also been rapid. The most mature of these are based on polycrystalline silicon (p - Si), amorphous silicon (a - Si), copper indium diselenide $SuInSe_2$(CIS), and cadmium telluride (CdTe). This paper explores the recent advances in the development of polycrystalline thin film solar cells.

• Journal of the Korea Institute of Military Science and Technology
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• v.15 no.4
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• pp.502-506
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• 2012

In order to find the structural characteristics of the thin films of group II-VI semiconductor compounds compared with those of powder materials, films were made of 4 powders of ZnS, CdS, CdSe, and CdTe(Aldrich), each with 99.99 % purity. For the ZnS/CdS multi-layers, the ZnS layer was coated over the CdS layer on an $AlO_x$ membrane, which served as a protective layer within a vacuum at the average speed of 1 ${\AA}$/sec. After studying the structures of the group II-VI semiconductor thin films by using X-ray spectroscopy, we found that the ZnS, ZnS/CdS, CdS, and CdSe films were hexagonal and exhibited some degree of preferred orientation. Also, the particles of the thin films of II-VI semiconductor compounds proved to be more homogeneous in size compared to those of the powder materials. These results were further verified through scanning electron microscopy(SEM), EDX analysis, and powder and thin film X-ray diffraction.

• 기계와재료
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• v.21 no.2
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• pp.74-83
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• 2009

유리나 금속판재와 같은 저가의 기판상에 박막재료를 코팅하여 제조하는 박막형 태양전지는 대면적 양산화를 통한저가격화 실현이 가능한 차세대 태양전지로 업계의 많은 관심을 끌고 있다. 본 기고에서는 박막형 태양전지로 분류되는 실리콘 박막태양전지, CIGS 태양전지, CdTe 태양전지, 염료감응형 태양전지 등의 기술 현황과 그 핵심 소재기술을 소개한다. 차세대 성장산업으로 기대되는 박막태양 전지 시장에서 국내 업체의 기술자립과 국제경쟁력 확보를 위해서는 핵심소재에 대한 원천기술 확보와 소재 및 설비의 국산화가 절실히 요구되는 시점이다.

• 한국전자현미경학회:학술대회논문집
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• 1997.11a
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• pp.29-32
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• 1997

• Proceedings of the Korean Vacuum Society Conference
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• 1998.06a
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• pp.96-96
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• 1998

• Proceedings of the Korean Vacuum Society Conference
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• 1994.02a
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• pp.82-83
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• 1994

• Proceedings of the Korean Vacuum Society Conference
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• 2003.02a
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• pp.151-151
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• 2003

• Electrical & Electronic Materials
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• v.24 no.10
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• pp.16-26
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• 2011

• 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%.