• Transactions of the Korean Society of Mechanical Engineers
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• v.14 no.1
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• pp.130-137
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• 1990

Thermal shock stress intensity factor for an edge-cracked plate subjected to thermal shock is obtained from Bueckner's weight function method. It is shown that thermal shock stress intensity factor has maximum values with variation of time and crack length and that there is most dangerous crack length. By comparing thermal shock stress intensity factor with fracture toughness, the fracture time and critical temperature difference due to thermal shock are determined theoretically. Under constant thermal shock temperature difference, and increase of crack length is shown to increase fracture time. The theoretical fracture time is compared with experimental value measured by acoustic emission method with soda lime glass.

• Proceedings of the Materials Research Society of Korea Conference
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• 2003.11a
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• pp.122-122
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• 2003

In recent years, there has been increasing interest in quasi one-dimensional nanostructural systems, because of their numerous potential applications in various areas, such as materials sciences, electronics, optics, magnetism and energy storage. Specifically, zinc oxide (ZnO) is recognized as one of the most promising oxide semiconductor materials, because of its good optical, electrical, and piezoelectrical properties. The ZnO nanorods were synthesized using vapor-solid (VS) mechanism on soda lime glass substrate without the presence of metal catalyst. ZnO nanorods were prepared thermal evaporation of a Zn powder at 500. As-fabricated ZnO nanorods had an average diameter and length of 40nm and 3$\mu\textrm{m}$. Transmission electron microscopy revealed that the ZnO nanorods were single crystalline with the growth direction perpendicular to the (101) lattice plane. The influences of reaction time on the formation of the ZnO nanorods were investigated. The Photoluminescence measurements showed that the ZnO nanorods had a strong ultraviolet emission at around 380nm and a green emission at around 500nm.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.02a
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• pp.683-683
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• 2013

박막태양전지의 일종인 CIGS 태양전지는 직접천이형 반도체로 광흡수계수가 $1{\times}10^5cm^{-1}$로 매우 높고, 전기광학적 안정성이 우수하여 실리콘 결정질 태양전지를 대체할 고효율 태양전지로 각광받고 있다. CIGS 태양전지는 광흡수층 공정방법에 따라 다양한 결정구조 및 효율 차이가 나타난다. 본 실험에서는 Sputtering방법으로 금속전구체를 증착하고, Sequential process를 이용하여 고온에서 셀렌화 열처리를 수행하였다. Soda-lime glass 기판에 배면전극으로 Mo를 증착하고, 1단계로 CuIn0.7Ga0.3 조성비의 타겟을 이용하여 Sputtering법으로 $1.0{\sim}1.2{\mu}m$두께의 CIG 전구체를 증착하였다. 2단계로 CIG 전구체에 분자빔증착기를 이용하여 Se를 증착하고, 열처리를 통하여 CIGS 화합물 구조의 박막을 형성시켰다.증착된 CIGS 박막은 광전자분광분석기로 원소의 화학적 결합상태를 확인하고, in-situ 엑스선회절분석을 통해 Se층의 증착두께와 열처리 온도 변화에 따른 CIGS 층의 결정구조 및 결정화도 변화를 분석하였다.

• 한국정보디스플레이학회:학술대회논문집
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• 2008.10a
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• pp.408-411
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• 2008

In an attempt to enhance luminance efficiency and to reduce discharge delays of test panels with aluminum fence-electrodes, various designs of the electrodes were prepared by chemically etching the aluminum foils bonded to soda-lime glass substrate via anodic bonding process. The effects of fence design on luminance and discharge characteristics were investigated and compared with conventional ac-PDPs. These results showed a possibility of using fence-type aluminum electrode at front plates of ac-PDDs without sacrificing its performance.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.17 no.8
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• pp.846-851
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• 2004

Transparent conducting indium tin oxide (TC-ITO) thin films on polymeric substrates have been deposited by a dc reactive magnetron sputtering without heat treatments. The polymeric substrates are acryl (AC), poly carbornate (PC), and polyethlene terephthalate (PET) as well as soda lime glass is also used to compare with the polymeric substrates. Sputtering parameters are an important factor for high quality of TC-ITO thin films prepared on polymeric substrates. Furthermore, the material, electrical and optical properties of as-deposited ITO films are dominated by the ratio of oxygen partial pressure. As the experimental results, the surface roughness of ITO films becomes rough as the oxygen partial pressure increases. The electrical resistivity of as-deposited ITO films decreases initially, and then increases with the increase of oxygen partial pressure. The optical transmittance at visible wavelength for all polymeric substrates is above 82 %.

• Transactions on Electrical and Electronic Materials
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• v.5 no.4
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• pp.153-157
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• 2004

ITO thin films were deposited on PET and soda-lime glass substrates by a dc reactive magnetron sputtering of In-Sn alloy metal target without substrate heater and post-deposition thermal treatment. The dependency of rf-bias voltage and substrate power during deposition processing was investigated to control the electrical and optical properties of ITO films. The range of rf bias voltage is from 0 to -80 V and the substrate power is applied from 10 to 50 W. The minimum resistivity of ITO film is 5.4${\times}$10$^{-4}$ $\Omega$cm at 50 W power and rf-bias voltage of -20 V. The best transmittance of ITO films at 550 nm wavelength is 91 % in the substrate power of 30 W and rf-bias voltage of -80 V.

• ETRI Journal
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• v.34 no.5
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• pp.779-782
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• 2012

$CuIn_{1-x}Ga_xSe_2$ (CIGS) thin films are grown on Mo/soda lime glass using a reactive sputtering process in which a Se cracker is used to deliver reactive Se molecules. The Cu and $(In_{0.7}Ga_{0.3})_2Se_3$ targets are simultaneously sputtered under the delivery of reactive Se. The effects of Se flux on film composition are investigated. The Cu/(In+Ga) composition ratio increases as the Se flux increases at a plasma power of less than 30 W for the Cu target. The (112) crystal orientation becomes dominant, and crystal grain size is larger with Se flux. The power conversion efficiency of a solar cell fabricated using an 800-nm CIGS film is 8.5%.

• Tribology and Lubricants
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• v.10 no.3
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• pp.62-70
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• 1994

An analytical model of the stress field caused by sliding indentation of brittle materials is developed. The complete stress field is treated as the superposition of applied normal and tangential forces with a sliding blister approximation of the localized inelastic deformation occuring just underneath the indenter. It is shown that lateral cracking is produced by the sliding blister stress field and that median cracking is caused by the applied contact forces. The model is combined with an experimental volume change measurements to show that the relative magnitude of tensile stresses governing lateral crack and median crack growth varies with the magnitude of the applied load. This prediction is consistent with the different regimes of experimentally observed cracking in soda-lime glass.

• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.1150-1151
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• 2008

Titanium-doped indium oxide (ITiO) films were prepared on soda-lime glass substrate using a magnetic null discharge (MND) sputter source. The ITiO thin films containing 10 wt.% Ti showed the minimum resistivity of ${\rho}=5.5{\times}10^{-3}{\Omega}cm$. The optical transmittance increases from 70% at 450 nm to 80% at 700 nm in visible spectrum. The surface roughness of the sample showed a change from 10 nm to 50 nm. The ITiO film used for TCO layer of DSCs exhibited an energy conversion efficiency of about 3.8 % at light intensity of 100 $mW/cm^2$.

• Proceedings of the Korean Vacuum Society Conference
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• 2010.08a
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• pp.258-258
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• 2010

ZnO TCO 박막은 후반사막과 전면전극의 물질으로써, 태양전지의 효율을 증가시킬수 있는 중요한 역할을 하고 있다. 특히 Boron 을 도핑한 BZO 박막은 가시광대 영역에서 높은 투명도를 보여준다. Soda Lime glass 위에 MOCVD를 이용하여 증착한 BZO 박막에 대해서, 플라즈마 처리에 의한 광학적 변화를 알아 보았다. 산소 또는 수소 분위기에서 플라즈마 처리를 하였고, 그에 따른 공정 조건 중 RF 전력, 압력, 시간을 제어했다. 이에 따라 ZnO 박막의 광학적 특성의 분석을 통해서 플라즈마 처리에 따른 흡수도와 밴드갭의 변화를 볼 수 있었다.