• Current Photovoltaic Research
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• 제3권3호
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• pp.97-100
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• 2015

The kesterite $Cu_2ZnSnSe_4$ (CZTSe) thin film solar cells were synthesized by selenization of sputtered Cu/Sn/Zn metallic precursors on Mo coated soda lime glass substrate in Ar atmosphere. Cu/Sn/Zn metallic precursors were deposited by DC magnetron sputtering process with 30 W power at room temperature. As-deposited metallic precursors were placed in a graphite box with Se pellets and selenized using rapid thermal processing furnace at various temperature ($480^{\circ}C{\sim}560^{\circ}C$) without using a toxic $H_2Se$ gas. Effects of Selenization temperature on the morphological, crystallinity, electrical properties and cell efficiency were investigated by field emission scanning electron microscope (FE-SEM) and X-ray diffraction (XRD), J-V measurement system and solar simulator. Further details about effects of selenization temperature on CZTSe thin films will be discussed.

• 한국자기학회:학술대회 개요집
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• 한국자기학회 2013년도 자성 및 자성재료 국제학술대회
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• pp.95-95
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• 2013

The NdFeB magnet can be classified into the sintered magnet and bonded magnet. The former has superior magnet characteristics but the degree of freedom in shape is highly restricted, whereas the latter has a high degree of freedom, but its magnet characteristics are inferior to the former. When a NdFeB magnet is used at the elevated temperature, part of Nd must be replaced with a high priced Dy to increase its coercive force. For these reasons, a Dy free and high performance NdFeB bonded magnet is desired strongly. The author successfully developed a Dy free NdFeB anisotropic bonded magnet based on discovery of new phenomena called as d-HDDR reaction and its mass production process such as a thermally balanced hydrogen reaction furnace, micro capsuled powder, compression molding / injection molding under magnetic field, magnetic die and so on. Applied to DC brush seat motor for automotive use, the motor has become 50% small in size and weight. The commercialization of a half sized motor for automotive use has been realized up to the market share of 30%. At present, its commercialization is extending to various types of motors such as power tool, ABS motor, wiper motor, window motor, electric bike power motor, and compressor motor. It is expected that the applications will be increasingly enlarged to EV motor, wind generator, EPS motor, washing machine, and glass cutting machine. This innovative technology has realized Dy free high performance magnet and mudt make big contribution to not only rare element strategies but also energy conservation.

• 한국표면공학회:학술대회논문집
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• 한국표면공학회 2016년도 추계학술대회 논문집
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• pp.134-134
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• 2016

The effect of different thermal treatments on the sub-50 nm copper nanoparticles is examined in the aspects of chemical, electrical and surface morphology. The copper nanoparticles are chemically synthesized and fabricated for paste-type solution. Simple bar coating method is practiced as a deposition process to form copper thin film on a typical slide glass. Deposited copper thin films are annealed by two different routes: general tube furnace with 99.99 % Ar atmosphere and selective laser sintering process. The thermal behavior of the different thermal-treated copper thin films is compared by SEM, XRD, FT-IR and XPS analysis. In this study, the laser sintering process ensures low annealing temperature, fast working speed and ambient-accessible route. Moreover, the laser-sintered copper thin film shows good electrical property and enhanced chemical stability than conventional thermal annealing process. Consequently, the proposed laser sintering process can be compatible with plastic substrate for flexible applications.

• 한국표면공학회지
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• 제43권1호
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• pp.7-11
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• 2010

Solid phase crystallization (SPC) is a simple method in producing a polycrystalline phase by annealing amorphous silicon (a-Si) in a furnace environment. Main motivation of the crystallization technique is to fabricate low temperature polycrystalline silicon thin film transistors (LTPS-TFTs) on a thermally susceptible glass substrate. Studies on SPC have been naturally focused to the low temperature regime. Recently, fabrication of polycrystalline silicon (poly-Si) TFT circuits from a high temperature polycrystalline silicon process on steel foil substrates was reported. Solid phase crystallization of a-Si films proceeds by nucleation and growth. After nucleation polycrystalline phase is propagated via twin mediated growth mechanism. Elliptically shaped grains, therefore, contain intra-granular defects such as micro-twins. Both the intra-granular and the inter-granular defects reflect the crystallinity of SPC poly-Si. Crystallinity and SPC kinetics of high temperatures were compared to those of low temperatures using Raman analysis newly proposed in this study.

• 한국전기전자재료학회논문지
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• 제24권9호
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• pp.766-772
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• 2011

Amorphous Si (a-Si) thin films of $p^+/p^-/n^+$ were deposited on $Si_3N_4$/glass substrate by using a plasma enhanced chemical vapor deposition (PECVD) method. These films were annealed at various temperatures and for various times by using a rapid thermal process (RTP) equipment. This step was added before the main thermal treatment to make the nuclei in the a-Si thin film for reducing the process time of the crystallization. The main heat treatment for the crystallization was performed at the same condition of $600^{\circ}C$/18 h in conventional furnace. The open-circuit voltages ($V_{oc}$) were remained about 450 mV up to the nucleation condition of 16min in the nucleation RTP temperature of $680^{\circ}C$. It meat that the process time for the crystallization step could be reduced by adding the nucleation step without decreasing the electrical property of the thin film Si for the solar cell application.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2007년도 추계학술대회 논문집
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• pp.358-360
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• 2007

For large scaled solar cells and photosensors CdS thin films of $2{\mu}m$ thickness have deposited on ITO glass substrate by chemical bath deposition methode in $300^{\circ}C$ electric furnace. The surface roughness and resistance of cadmium sulphide(CdS) thin films with different microstructures and morphologies was investigated by using a x-ray diffraction (XRD), a scanning electron microscope (SEM), an atomic force microscope (AFM), and a near-field scanning microwave microscope (NFMM). As the different substrate heat temperatures, the microwave reflection coefficient $S_{11}$ and intensity of the (002) diffraction peak was changed, and the surface morphology also has shown differently.

• 한국표면공학회지
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• 제25권5호
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• pp.215-221
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• 1992

This research is aimed at developing(110) preferred TiS2 cathode films and glass typed solid electro-lytes which have high ionic migrations and low electron conductivities for thin secondary solid batteries. To obtain preferred oriented TiS2 thin films on a substrate by CVD method using TiCl4 and H2S gases three factors of heating temperature, inner pressure of furnace and TiCl4/H2S gas mole fraction were ex-amined systematically. To obtain solid films of Li2O-B2O3-SiO2 electrolytes by r.f. sputtering for thin proto-type batteries of Li/Li2O-B2O3-SiO2TiS2, sputtering conditions were examined. TiS2 cathode films showed columnar structure, namely c axis oriented parallely. At low pressure of reaction chamber and low heating temperature, surface of smooth TiS2 films couldd be obtained. Ionic conductivity of Li2O-B2O3-SiO2 films manufactured by r.f. magnetron sputtering were 3$\times$10-7$\Omega$-1cm-1 and electron conductivities were 10-11$\Omega$-1cm-1. Open cell voltage of thin lithium batteries were 2.32V with a designed prototype cell.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2010년도 추계학술대회 초록집
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• pp.42.2-42.2
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• 2010

Transparent conducting oxides (TCOs) are of significant importance for their applications in various devices, such as light-emitting diodes, thin-film solar cells, organic light-emitting diodes, liquid crystal displays, and so on. In order for TCOs to contribute to the performance improvement of these devices, TCOs should have high transmittance and good electrical properties simultaneously. Sn-doped $In_2O_3$ (ITO) is the most commonly used TCO. However, indium is toxic and scarce in nature. Thus, ZnO has attracted a lot of attention because of the possibility for replacing ITO. In particular, group III impurity-doped ZnO showed the optoelectronic properties comparable to those of ITO electrodes. Al-doped ZnO exhibited the best performance among various doped ZnO films because of the high substitutional doping efficiency. However, in order for the Al-doped ZnO to replace ITO in electronic devices, their electrical and optical properties should further significantly be improved. In this connection, different ways such as a variation of deposition conditions, different deposition techniques, and post-deposition annealing processes have been investigated so far. Among the deposition methods, RF magnetron sputtering has been extensively used because of the easiness in controlling deposition parameters and its fast deposition rate. In addition, when combined with post-deposition annealing in a reducing ambient, the optoelectronic properties of Al-doped ZnO films were found to be further improved. In this presentation, we deposited Al-doped ZnO (ZnO:$Al_2O_3$ = 98:2 wt%) thin films on the glass and sapphire substrates using RF magnetron sputtering as a function of substrate temperature. In addition, the ZnO samples were annealed in different conditions, e.g., rapid thermal annealing (RTA) at $900^{\circ}C$ in $N_2$ ambient for 1 min, tube-furnace annealing at $500^{\circ}C$ in $N_2:H_2$=9:1 gas flow for 1 hour, or RTA combined with tube-furnace annealing. It is found that the mobilities and carrier concentrations of the samples are dependent on growth temperature followed by one of three subsequent post-deposition annealing conditions.

• 한국포장학회지
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• 제24권2호
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• pp.65-71
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• 2018

생산자 책임 재활용제도(EPR)의 재활용의무대상 품목은 포장재군에 따라 종이팩, 유리병, 금속캔, 합성수지포장재 구분되어질 수 있다. 폐종이팩의 경우 압축된 종이팩을 해리하여 폴리에틸렌 필름 및 기타 이물질을 분리하고 세척, 분쇄, 건조과정을 거쳐 화장지 원단으로 제작한 후 다양한 화장지로 가공 생산하고 있다. 그러나 알루미늄 호일이 첩합된 종이팩은 재활용 공정 중 잔유물이 발생하여 화장지의 품질을 저해하고 제품 편의성을 위해 부착된 마개, 스트로우와 같은 새로운 성형구조의 제품들은 재활용 공정에서 수작업의 과정을 추가하여 재활용 수율을 낮추는 문제점이 있다. 유리병은 재사용과 재활용으로 구분가능하며 재사용은 주류, 음료병들이 대상이고 재활용은 1회용 유리병이나 깨진 유리병을 대상으로 하고 있다. 유리병 재활용은 폐유리병 회수 과정, 이물질 제거, 색상별 분류, 파쇄, 원료화 과정을 거쳐 제병업체에 공급되며, 철금속성분 제거, 저비중 물질 제거 등을 제외하고 대부분 수작업에 의존한다. 유리병은 무색 계열, 갈색 계열, 녹색 계열의 색상이 주를 이루고 있으며 재활용 과정에서 주된 3색 이외의 색상의 경우 재생원료의 품질을 저해시키는 원인이 되고 있다. 합성수지 라벨의 다량 접착제와 병의 직접 인쇄는 잉크의 색상에 의하여 품질저하가 발생하며, 유리병에 사용되는 플라스틱 마개 또한 재활용 공정에서 이물질 제거과정을 어렵게 한다. 금속캔은 자동선별기를 통해서 철캔과 알루미늄캔을 분류한 후 압축하여 용광로를 통해 철, 알루미늄으로 재생산된다. 재활용 공정에서 가공육 알루미늄 캡의 플라스틱 뚜껑은 선별이 어렵기 때문에 플라스틱 뚜껑을 사용하지 않거나 분리 배출할 수 있는 방안이 필요하며 금속캔 또한 금속이 아닌 마개, 라벨이 재활용 공정에서 수작업 공정을 추가로 필요하게 하고 있다. 합성수지 포장재 중 복합재질의 경우 선별된 압축품을 파쇄한 뒤 용융성형을 통한 물질 재활용, 열분해를 통한 유화, 압축성형을 통한 고형연료 제조단계를 통해 재생제품을 생산하며, 단일 합성수지는 자력선별, 풍력선별, 비중선별 등 다양한 방법을 통해 선별공정을 거처 압축, 파쇄, 세척, 용융압출, Pellet 형태의 재생 원료를 만드는 물질 재활용 과정을 거친다. 종이, 금속 라벨, 복합재질 리드 등은 합성수지 재활용에 문제를 발생시키는 요인으로 비중 1미만의 비수분리성 접(참)착식 라벨의 경우가 이에 해당한다. 이 연구를 통해 종이팩, 유리병, 금속캔, 합성수지의 재활용 공정 모두 재활용 대상과 다른 물질의 유입이 재활용공정을 방해하거나 재활용 비용, 시간을 증대시키고 있음을 확인하였다. 각 포장재별로 종이팩 포장재의 스트로우를 비롯한 합성수지 성형구조물과 금속과 유리병 포장재의 이물질을 포함한 라벨과 마개 및 잡자재 그리고 합성수지 포장재의 금속, 종이 복합재질이 이에 해당하였다. 따라서 재활용 산업의 활성화를 위해서는 제품이나 포장재의 설계 단계에서부터 재활용에 용이한 재질 구조가 요구되어지며, 정부차원의 지원과 관련 법 제도 개선이 필요하다.

• 한국재료학회지
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• 제3권1호
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• pp.12-18
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• 1993

단결정 실리콘위에 스퍼터법으로 증착된 티타니움막을 급속가열로에서 고상반응에 의해 형성시킨 면저항 1.2 ohm/sq. 내외의 TiS$i_2$ 박막에 있어서 열안정성을 상부절연막의 유무 및 종류에 따라 조사하였다. 상부절연막은 상압 CVD로 증착한 USG(Undoped Silicate Glass, Si$i_2$) 막과 플라즈마 CVD법으로 증착한 PE-SiN(S$i_3$$N_4$)막을 사용했다. 열안정성 평가는 90$0^{\circ}C$에서 시간을 달리하여 TiS$i_2$막, PE-SiN막, USG막의 스트레스는 각각 1.3${\times}{10^{9}}$, 1.25 ${\times}{10^{10}}$, 2.26 ${\times}{10^{10}}$ dyne/c$m^2$의 인장응력을 나타내었다. 응집현상은 TiS$i_2$의 응집현상은 Nabarro-Herring 마이크로 크리프에 의한 원자의 확산관점에서 검토되었다.