• 한국진공학회:학술대회논문집
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• 한국진공학회 2014년도 제46회 동계 정기학술대회 초록집
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• pp.318.2-318.2
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• 2014

The high contact resistance is still one of the major issues to be resolved in CdS/CdTe thin film solar cells. CdTe/Metal Schottky contact induced a high contact resistance in CdS/CdTe solar cells. It has been reported that the work function of CdTe thin film is more than 5.7 eV. There has not been a suitable back contact metal, because CdTe thin film has a high work function. In a few decades, some buffer layer was reported to improve a back contact problem. Buffer layers which are Te, $Sb_2Te_3$, $Cu_2Te$, ZnTe:Cu and so on was inserted between CdTe and metal electrode. A formed buffer layers made a tunnel junction. Hole carriers which was excited in CdTe film by light absorption was transported from CdTe to back metal electrode. In this report, we reported the variation of solar cell performance with different buffer layer at the back contact of CdTe thin film solar cell.

• 한국분말재료학회지
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• 제29권1호
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• pp.41-46
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• 2022

In this study, we report the microstructure and characteristics of Ag-SnO₂-Bi₂O₃ contact materials using a controlled milling process with a subsequent compaction process. Using magnetic pulsed compaction (MPC), the milled Ag-SnO₂-Bi₂O₃ powders have been consolidated into bulk samples. The effects of the compaction conditions on the microstructure and characteristics have been investigated in detail. The nanoscale SnO₂ phase and microscale Bi2O3 phase are well-distributed homogeneously in the Ag matrix after the consolidation process. The successful consolidation of Ag-SnO₂-Bi₂O₃ contact materials was achieved by an MPC process with subsequent atmospheric sintering, after which the hardness and electrical conductivity of the Ag-SnO₂-Bi₂O₃ contact materials were found to be 62-75 HV and 52-63% IACS, respectively, which is related to the interfacial stability between the Ag matrix, the SnO₂ phase, and the Bi₂O₃ phase.

• Tribology and Lubricants
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• 제5권1호
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• pp.28-35
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• 1989

The wear tests of ceramic materials in dry rolling contact were carried out at room temperature to investigate their macroscopic wear characteristics. Both point contact and line cootact were adapted in the wear tests of them. Ceramic materials used in these tests were silicon nitride, silicon carbide, cermet of TiN and TiC, titania, and alumina. The wear test of the bearing steel was carried out to compare to the wear test results of the ceramic materials. The results showed that the wear rate of silicon nitride was smaller than any other ceramic materials and bearing steel. In the steady wear, the wear volume of ceramic materials increases linearly with the rolling distance. It was also found from the experimental results that fracture toughness and surface roughness dominate the wear process of ceramic materials in dry rolling contact.

• 한국산학기술학회:학술대회논문집
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• 한국산학기술학회 2011년도 춘계학술논문집 2부
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• pp.683-686
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• 2011

The effect of welding material such as welding wires and materials for contact tip on the contact tip wear was investigated. Two types welding wires such as solid and flux cored wire and a variety of contact tips made of Cu-P, Cu-Cr(0.25%), Cu-Cr(1%) and Cu-Cr-Zr were employed for the comparison of wear resistance. It was found that the wear resistance of contact tips materials was Cu-Cr-Zr, Cu-Cr(1%), Cu-Cr(0.25%), Cu-P in order while the solid wire had a better wear resistance than flux cored wire.

• Bulletin of the Korean Chemical Society
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• 제30권4호
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• pp.882-886
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• 2009

The electrode contact poling is one of the efficient tools to induce a stable polar order of nonlinear optical (NLO) chromophores in the solid film. Self-assembled NLO chromophores with high electro-optic (E-O) activities were utilized for quantitative determination of the chromophore order induced under contact poling by spectroscopic changes. We found that NLO chromophores rarely decompose under the high electric field during contact poling. The absorption spectra were de-convoluted into a sum of Gaussian components to separate energy transitions for a binary composite system which contains a secondary guest chromophore AJC146 in the self-assembled chromophore HDFD. Poling efficiency was significantly improved in the binary system compared to the individual components.

• 대한금속재료학회지
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• 제46권12호
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• pp.817-822
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• 2008

Metal matrix composite (MMC) materials having low electrical contact resistance based on 316L stainless steel (STS) matrix alloy with $ZrB_2$ particles were fabricated for PEMFC (Polymer Electrolyte Membrane Fuel Cell) separator by powder metallurgy (PM). The effects of the boride particle addition into the matrix alloy on microstructure, surface morphology, and interfacial contact resistance (ICR) between the samples and gas diffusion layer (GDL) were investigated. Both conventional and PM 316L STS samples showed high ICR due to the existence of non-conductive passive film on the alloy surface. The addition of the boride particles, however, remarkably reduced ICR of the samples. SEM observation revealed that the boride particles were protruded out of the matrix surface and particle density existing on the surface increased with increasing the boride content, causing increase of the total contact area between the conductive particles and GDL. ICR of the samples also decreased with increasing the boride content resulted from the increased contact area.

• 태양에너지
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• 제17권1호
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• pp.17-26
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• 1997

단결정 실리콘 태양전지는 PESC(Passivated Emitter Solar Cell), PERC(Passivated Emitter and Rear Cell), Point Contact Cell, PERL(Passivated Emitter and Rear Locally-Diffused Cell) 형태로 기술적인 발전을 해왔다. BCSC(Buried Contact Solar Cell)는 낮은 제조 단가로 높은 효율을 얻을 목적으로 개발되었으며 개량된 형태인 DSBC(Double Sided Buried Contact Cell)는 양면으로 빛을 흡수할 수 있는 장점이 있다.

• Tribology and Lubricants
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• 제31권4호
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• pp.163-169
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• 2015

This paper describes a design method for the corner radius of a contacting body using the theoretical approach of contact mechanics. A complete contact, as in the case of a sharp-cornered punch, produces singular contact traction: whereas, in an incomplete contact, the singular contact traction disappears because of the rounded corners, and the contact edges are within the rounded regions. The design method aims to determine the conditions of the contact force as well as the material properties in an incomplete contact. The incomplete contact changes into the complete contact again when the contact edges exceed the rounded regions owing to either an increased contact force or the compliance of the materials. The contact length of a rounded punch is used as a parameter to derive the required conditions. As a result, a design formula is obtained, which provides a minimum allowable radius when the materials, normal contact force, and the length of a flat region of the punch are predetermined. This work consists of two parts: Part I includes a theoretical background, design method, and formula, and Part II describes the actual process with the investigation of design parameters.

• Current Photovoltaic Research
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• 제3권1호
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• pp.10-15
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• 2015

Cu doping by copper or $Cu_2Te$ materials enhances p+ formation in CdTe near the back contact interface, allowing better formation of ohmic contact. However, the Cu in CdTe junction is also considered as a principal component of CdTe cell degradation. In this paper, Na-doped ZnTe layer was employed as a back contact material to improve the stability of CdTe solar cells. As a process variable, post $CdCl_2$ treatment of CdS/CdTe film was conducted before or after depositing ZnTe:Na on CdTe. The change of the photovoltaic properties of CdTe cells were investigated with aging time. Low-temperature photoluminescence analysis was conducted to describe the degradation mechanism. The result showed that the CdTe solar cells with better stability compare to Cu contact were achieved using an optimized ZnTe:Na back contact.

• 한국표면공학회:학술대회논문집
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• 한국표면공학회 2009년도 추계학술대회 초록집
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• pp.156-156
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• 2009

High efficiency silicon solar cell technology based on planar technology has been improved by various kinds of process by using the wet etching process. In particular, the buried contact solar cell has been successfully studied. In the present work, a simplified process of the buried contact solar cell has been suggested to help one design effectively the high-efficiency solar cell.