• Journal of the Korean Solar Energy Society
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• v.39 no.1
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• pp.1-9
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• 2019

Light induced degradation is one of the major research challenges of hydrogenated amorphous silicon related thin film silicon solar cells. Amorphous silicon shows creation of metastable defect states, originating from elevated concentration of dangling bonds during light exposure. The metastable defect states work as recombination centers, and mostly affects quality of intrinsic layer in solar cells. In this paper we present results of light induced degradation in thin film silicon solar cells and discussion on physical origin, mechanism and practical solutions of light induced degradation in thin film silicon solar cells. In-situ light-soaking IV measurement techniques are presented. We also present thin film silicon material with silicon nano-quantum dots embedded within amorphous matrix, which shows superior stability during light-soaking. Our results suggest that solar cell using silicon nano-quantum dots in abosrber layer shows superior stability under light soaking, compared to the conventional amorphous silicon solar cell.

• Trans-
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• v.1
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• pp.45-66
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• 2016

The study uses the image technique of the movie (analysis) since there are limited analyses and data of the dance film's (cinematic) grammar. The films are limited to the Wim Vandekeybus's Blush. From the analysis of the one film, films are directed using basic movie grammars. Although the films are of the same genre, it differs from the method of using image techniques as well as the director's personal art preference. The cinematic grammars enhance the effect of the movement and it emphasizes the objectives to deliver the audience true meaning of the films. Dance film is not a simple word combination of dance and film to record new type of art; dance is used for the movie's artistic and aesthetic enhancement. To find out dance is the language and important expressive tool of the dance film, at the same time cinematic grammar enhances effect of dance and objective of the film, the study uses image technique analysis. These are the results of dance film analysis by using image techniques. Firstly, Dance film can transcend time and space. Secondly, The creative director could emphasize some part that the audience should focus on to clearly deliver the intention of the choreographer. Lastly, To popularize the dance genre. If the dance film produces with more diversified stories than the resent, it will be a part of a cultural industry and could create profits. Dance film might lose the sense of realism, which is the main characteristic of the stage art; however it could feel the beauty of the film through the mise en scene.

• Transactions of the Korean hydrogen and new energy society
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• v.24 no.4
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• pp.282-287
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• 2013

Hydrogen production from water using solar energy is attractive way to obtain clean energy resource. Among the various solar-to-hydrogen production techniques, a combination of a photovoltaic and an electrolytic cell is one of the most promising techniques in term of stability and efficiency. In this study, we show successful fabrication of precursor solution processed CIGS thin film solar cells which can generate high voltage. In addition, CIGS thin film solar cell modules producing over 2V of open circuit voltage were fabricated by connecting three single cells in series, which are applicable to water electrolysis. The operating current and voltage during water electrolysis was measured to be 4.23mA and 1.59V, respectively, and solar to hydrogen efficiency was estimated to be 3.9%.

• Proceedings of the Materials Research Society of Korea Conference
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• 1992.05a
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• pp.6-6
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• 1992

Ionized cluster beam deposition (ICBD) technique has been employed to fabricate high-purity crystalline polyimide (PI) film. The pyromellitic dianhydride (PMDA) and oxydianiline (ODA) were deposited using dual ICB sources, Fourier trans forminfraredspectroscopy (FT-IR), X-ray photoemission spectroscopy (XPS), and Transmission electron microscopy (TEM)study show that the bulk and surface chemical properties and the crystalline structure are very sensitive to the ICBD conditions such as cluster ion acceleration voltage and ionization voltage, At optimum ICBD conditions, the PI films have a maximum imidization, negligible impurities(∼1% isoimide), and a good crystalline structure probably due to the high surface migration energy and surface cleaning effect. These characteristics are superior to those of films deposited by other techniques such as colvent cast, vapowr deposition, or sputtering techniques.

• Journal of Mechanical Science and Technology
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• v.20 no.10
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• pp.1670-1679
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• 2006

The development of the oxidation, wear and corrosion resistant materials that could be used in severe environmental conditions is needed. The elementary technologies for surface modification include ion implantation and/or thin film coating. Furthermore, in order to develop ion implantation technique to the specimens with three-dimensional shapes, plasma-based ion implantation (PBII) techniques were investigated. As a result, it was found that the ion implantation and/or thin film coating used in this study were/was effective for improving the properties of materials, which include implantations of various kinds of ions into TiAl alloy, TiN films formed on surface of base material and coatings in high-temperature steam. The techniques proposed in this study provide useful information for all of the material systems required to use at elevated temperature. For the practical applications, several results will be presented along with laboratory test results.

• Journal of the Korean Society for Precision Engineering
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• v.21 no.7
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• pp.171-178
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• 2004

Techniques and procedures are presented for measuring mechanical properties on thin-film Polysilicon. Narrow platinum lines are deposited 250 ${\mu}{\textrm}{m}$ apart on tensile specimens that are 3.5 ${\mu}{\textrm}{m}$ thick and 600 ${\mu}{\textrm}{m}$ wide. Load is applied by a piezo-actuator and by hanging weights. Strain is measured by an ISDC at temperatures up to 500 $^{\circ}C$. Measurements of the elastic modulus with jig modifications, loading speed and temperature change are presented first. And then, the preliminary data for the coefficient of thermal expansion and creep behavior are presented as a reference.

• Journal of the Semiconductor & Display Technology
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• v.10 no.3
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• pp.7-13
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• 2011

In Korea, the car mobile phone service had started in 1961 and with this Korea Mobile Telecommunications Services was established in 1984. Its service was mainly focused on the mobile phone service for the car which led the popularity of the full-scale mobile phone service. There are many kinds of materials, colors and patterns which are the elements of surface coating techniques. In light of that, we are focused on the UV coating that is ranked as an important part of the techniques in this study. In the first, the use of various materials for the cellular phone and surface processing techniques for the cellular phone were searched. On the basis of the results, the experiments of actual consumer experience with the exfoliation of the surface were done and through that we proposed the best way of processing the surface for the cellular phone and the materials. The result of the Wear Test showed that thick coating was detached more slowly and each company differed in their results with UV paints despite the same thickness of UV coating. The seal (UV) exfoliation of cellular phone is deeply related with the film thickness and the film formation when the users use the cellular phones and the exfoliation of the cellular phone surface will be decreased if the manufacturers meet the best conditions for the cellular phone.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.16 no.1
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• pp.103-112
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• 1986

The purpose of this study was to investigate the numbers and causes of retakes in 300 complete mouth radiographic surveys made by 75 senior dental students. According to radiographic techniques and film holding methods, they were divided into 4 groups: Group Ⅰ: Bisecting-angle technique with patient's fingers. Group Ⅱ: Bisecting-angle technique with Rinn Snap-A-Ray device. Group Ⅲ: Paralleling technique with Rinn XCP instrument (short cone) Group Ⅳ: Paralleling technique with Rinn XCP instrument (long cone) The most frequent cause of retakes, the most frequent tooth area examined, of retakes and average number of retakes per complete mouth survey were evaluated. The obtained results were as follows: Group Ⅰ: Incorrect film placement(47.8%), upper canine region, and 0.89 Group Ⅱ: Incorrect film placement (44.0%), upper molar region, and 1.12. Group Ⅲ: Incorrect film placement (79.2%), upper molar region, and 2.05 Group Ⅳ: Incorrect film placement (67.7%), upper molar region, and 1.69. The average number of retakes per complete mouth survey of paralleling technique (Group Ⅲ＋Ⅳ) was higher than that of bisecting-angle technique (Group Ⅰ ＋ Ⅱ) (p<0.01). There was no difference between Group Ⅰ and Group Ⅱ, and between Group Ⅲ and Group Ⅳ in the average number of retakes per complete mouth survey (p>0.05).

• Proceedings of the Korean Vacuum Society Conference
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• 1994.06a
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• pp.85-86
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• 1994

• The Korean Journal of Ceramics
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• v.3 no.2
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• pp.92-95
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• 1997

Because of the novel characteristics such as chemical stability, hardness, electrical resistivity and thermal conductivity, diamond-like carbon (DLC) film is a suitable material for the passivation layers. For this purpose, using the PECVD, DLC films were synthesized at room temperature. The adhesion and the hardness of the DLC films deposited on Si an SiO2 substrate were measured. The resistivity of 5.3$\times$$10^8$$\Omega$.cm was measured by automatic spreading resistance probe analysis method. The thermal conductivities of different DLC films were measured and compared with that of phospho silicate glass (PSG) film which is commonly used as passivation layers. The thermal conductivity of DLC film was improved by increasing hydrogen flow rate up to 90 sccm and was better than that of PSG film. The patterning techniques of the DLC film developed using the RIE and the lift-off method to form 5$\mu\textrm{m}$ line. Finally, the thermal characteristics of the power transistor with the DLC film as passiviation layer was analyzed.