• 설비공학논문집
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• 제25권11호
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• pp.573-577
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• 2013

An external window directly affects the energy performance of its building. In modern well-insulated buildings, U-values for walls of 0.36 $W/m^2K$ or even lower can be realized. In such buildings, glazing with typical U-value of 2.1 $W/m^2K$ or higher creates thermal weak spots on the facade. The performance of the existing triple glass window has been limited to energy savings and condensation prevention. In this study, the performance of condensation prevention of a vacuum multi-layer glass was analyzed. The final conclusion through mock-up experiments is as follows. The surface temperature of the vacuum multi-layer glass was $2^{\circ}C$ higher, and the temperature difference ratio (TDR) was 0.07 lower, than the corresponding values of the triple glass.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1998년도 추계학술대회 논문집 학회본부 C
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• pp.792-794
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• 1998

The TPD and the $Alq_3$ film are widely used as a hole transport layer and an emitter layer respectively, in organic electroluminescent(EL) device (ITO Glass/TPD/$Alq_3$/metal). In this structure, we fabricated two models. Model(1) having ITO glass/$Alq_3$/Al structure and model(2) having ITO Glass/TPD/$Alq_3$/Al structure were fabricated by the vacuum evaporation. The comparison between model(1) and model(2) was made about the absorbance, the wave length, the current-voltage characteristic and the ln I - $V^{(1/2)}$characteristic respectively. Electroluminescence of green and wavelength of 510[nm] were observed in both model. We observed absorbance from 320[nm] to 430[nm] in $Alq_3$ material and from 250[nm] to 400[nm] in TPD material.

• 한국진공학회지
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• 제22권6호
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• pp.298-305
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• 2013

스토버 방법(St$\ddot{o}$ber method)을 이용하여 균일한 크기의 실리카 나노비드(silica nanobead)를 합성하였으며 초음파(sonication) 방법을 이용하여 분자 처리된 유리 기판 위에 실리카 나노비드를 단층(monolayer)으로 정렬시켰다. 유리기판위에 처리된 분자층은 3-chloropropyltrimethoxysilane (CP-TMS)와 polyethyleneimine (PEI)가 사용되어졌고 합성된 나노비드는 톨루엔에 분산시킨 뒤 초음파방법으로 유기기판위에 부착되어졌다. 수행되어진 초음파방법은 분자 처리된 유리 기판을 단독으로 사용하는 SO (sonication without stacking) 모드와 두 개의 깨끗한 유리 기판 사이에 분자 처리된 유리 기판을 삽입하여 사용하는 SS (sonnication with stacking) 모드로 구분지어 적용되었으며, 기판위에 정렬된 실리카 나노비드의 무게는 마이크로 저울(microbalance)을 이용하여 측정한 뒤 점유도(degree of coverage, DOC)를 계산하였다. 결론적으로, SO 모드에서는 DOC가 단기간에 가파르게 상승하여 140% 이상까지 도달했지만 다층(multi-layer)구조가 많이 발견되는 특징이 있었고, SS 모드에서는 DOC가 평형에 도달하는 시간이 SO 모드보다 느리게 진행되었지만 보다 밀집(close-packing)된 형태의 단층구조가 관측되었다.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2015년도 제49회 하계 정기학술대회 초록집
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• pp.150.2-150.2
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• 2015

In this study, we analyzed the electric and optical characteristics by using various deposition rate ($0.5{\AA}$, $1.0{\AA}$ and $1.5{\AA}/s$) in order to enhance the performance in organic light-emitting devices (OLED). The organic multi-layer structures were deposited with NPB ($500{\AA}$ as hole transport layer), Alq3 ($600{\AA}$ as electron transport layer and emission layer) and LiF ($8{\AA}$ as electron injection layer) via SUNIC PLUS200 on Glass/ITO substrates. In this experiment, we examined the relationship between porous state of organic deposition and mobility of the organic materials. Among the three deposition rates, $0.5{\AA}/s$ achieved the highest performance of (10,786cd/m2, 4.387cd/A) comparing with that of $1{\AA}/s$ (7,779cd/m2, 3.281cd/A) and $1.5{\AA}/s$ (5,167cd/m2, 2.693cd/A). We confirmed that low deposition rate helps to arrange organic materials densely and to move easily another atomic location using inter-chain transporting by orbital overlap.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2000년도 제18회 학술발표회 논문개요집
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• pp.210-210
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• 2000

Vertically well aligned multi-wall carbon nanotubes (CNT) were grown on nickel coated glass substrates by plasma enhanced hot filament chemical vapor deposition at low temperatures below 600$^{\circ}C$. Acetylene and ammonia gas were used as the carbon source and a catalyst. Effects of growth parameters such as pre-treatment of substrate, plasma intensity, filament current, imput gas flow rate, gas composition, substrate temperature and different substrates on the growth characteristics of CNT were systematically investigated. Figure 1 shows SEM image of CNT grown on Ni coated glass substrate. Diameter of nanotube was 30 to 100nm depending on the growth condition. The diameter of CNT decreased and density of CNT increased as NH3 etching time etching time increased. Plasma intensity was found to be the most critical parameter to determine the growth of CNT. CNT was not grown at the plasma intensity lower than 500V. Growth of CNT without filament current was observed. Raman spectroscopy showed the C-C tangential stretching mode at 1592 cm1 as well as D line at 1366 cm-1. From the microanalysis using HRTEM, nickel cap was observed on the top of the grown CNT and very thin carbon amorphous layer of 5nm was found on the nickel cap. Current-voltage characteristics using STM showed about 34nA of current at the applied voltage of 1 volt. Electron emission from the vertically well aligned CNT was obtained using phosphor anode with onset electric field of 1.5C/um.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2009년도 제38회 동계학술대회 초록집
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• pp.97-97
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• 2010

We demonstrate the hybrid polymer-quantum dot based multi-functional device (Organic bistable devices, Light-emitting diode, and Photovoltaic cell) with a single active-layer structure consisting of CdSe/ZnS semiconductor quantum-dots (QDs) dispersed in a poly N-vinylcarbazole (PVK) and 1,3,5-tirs- (N-phenylbenzimidazol-2-yl) benzene (TPBi) fabricated on indium-tin-oxide (ITO)/glass substrate by using a simple spin coating technique. The multi-functionality of the device as Organic bistable device (OBD), Light Emitting Diode (LED), and Photovoltaic cell can be successfully achieved by adding an electron transport layer (ETL) TPBi to OBD for attaining the functions of LED and Photovoltaic cell in which the lowest unoccupied molecular orbital (LUMO) level of TPBi is positioned at the energy level between the conduction band of CdSe/ZnS and LiF/Al electrode (band-gap engineering). Through transmission electron microscopy (TEM) study, the active layer of the device has a p-i-n structure of a consolidated core-shell structure in which semiconductor QDs are uniformly and isotropically adsorbed on the surface of a p-type polymer core and the n-type small molecular organic materials surround the semiconductor QDs.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2012년도 제43회 하계 정기 학술대회 초록집
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• pp.389-390
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• 2012

In this study, we fabricate a superhydrophobic surface made of hierarchical nanostructures that combine wax crystalline structure with moth-eye structure using vacuum cluster system and measure their hydrophobicity and durability. Since the lotus effect was found, much work has been done on studying self-cleaning surface for decades. The surface of lotus leaf consists of multi-level layers of micro scale papillose epidermal cells and epicuticular wax crystalloids [1]. This hierarchical structure has superhydrophobic property because the sufficiently rough surface allows air pockets to form easily below the liquid, the so-called Cassie state, so that the relatively small area of water/solid interface makes the energetic cost associated with corresponding water/air interfaces smaller than the energy gained [2]. Various nanostructures have been reported for fabricating the self-cleaning surface but in general, they have the problem of low durability. More than two nanostructures on a surface can be integrated together to increase hydrophobicity and durability of the surface as in the lotus leaf [3,5]. As one of the bio-inspired nanostructures, we introduce a hierarchical nanostructure fabricated with a high vacuum cluster system. A hierarchical nanostructure is a combination of moth-eye structure with an average pitch of 300 nm and height of 700 nm, and the wax crystalline structure with an average width and height of 200 nm. The moth-eye structure is fabricated with deep reactive ion etching (DRIE) process. $SiO_2$ layer is initially deposited on a glass substrate using PECVD in the cluster system. Then, Au seed layer is deposited for a few second using DC sputtering process to provide stochastic mask for etching the underlying $SiO_2$ layer with ICP-RIE so that moth-eye structure can be fabricated. Additionally, n-hexatriacontane paraffin wax ($C_{36}H_{74}$) is deposited on the moth-eye structure in a thermal evaporator and self-recrystallized at $40^{\circ}C$ for 4h [4]. All of steps are conducted utilizing vacuum cluster system to minimize the contamination. The water contact angles are measured by tensiometer. The morphology of the surface is characterized using SEM and AFM and the reflectance is measured by spectrophotometer.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2009년도 제38회 동계학술대회 초록집
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• pp.151-151
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• 2010

In this paper, the electrically properties of nonvolatile memory (NVM) using multi-stacks gate insulators of oxide-nitride-oxynitride (ONOn) and active layer of the low temperature polycrystalline silicon (LTPS) were investigated. From hydrogenated amorphous silicon (a-Si:H), the LTPS thin films with high crystalline fraction of 96% and low surface's roughness of 1.28 nm were fabricated by the metal induced crystallization (MIC) with annealing conditions of $650^{\circ}C$ for 5 hours on glass substrates. The LTPS thin film transistor (TFT) or the NVM obtains a field effect mobility of ($\mu_{FE}$) $10\;cm^2/V{\cdot}s$, threshold voltage ($V_{TH}$) of -3.5V. The results demonstrated that the NVM has a memory window of 1.6 V with a programming and erasing (P/E) voltage of -14 V and 14 V in 1 ms. Moreover, retention properties of the memory was determined exceed 80% after 10 years. Therefore, the LTPS fabricated by the MIC became a potential material for NVM application which employed for the system integration of the panel display.

• 마이크로전자및패키징학회지
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• 제10권1호
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• pp.1-5
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• 2003

본 연구에서는 ITO (indium tin oxide)/glass 투명기판 위에 다층구조의 OELD (organic electroluminescent devices) 소자를 진공 열증착법으로 제작하였다. 발광층 재료로서 Alq$_3$(tris-(8-hydroxyquinoline)aluminum)물질을 사용하였고, 정공수송층으로는 TPD (triphenyl-diamine) 및 $\alpha-NPD$를 사용하였다. 정공주입층 재료로서 CuPc (Copper phthalocyanine)를 사용하였다. 또한 QD2(quinacridone2) 물질을 $Alq_3$ 발광층내에 약 $10\AA$ 두께로 증착하여 발광효율 향상을 시도하였다. 제작된 모든 소자의 발광개시전압은 약 7 V 이었으며, 정공수송층으로 TPD 물질대신에 열적안정성이 우수한 $\alpha-NPD$를 사용한 경우 휘도값과 발광효율이 개선되었다. $Alq_3$ 발광층 사이에 QD2 물질을 적층한 소자에서 발광효율은 1.55 lm/W 값을 나타내어 $Alq_3$ 발광층만을 사용한 경우에 비해 약 8배 발광효율이 향상되었다.

• 대한전자공학회논문지
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• 제23권5호
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• pp.699-705
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• 1986

Sb2S3 thin films were fabricated by vacuum evaporation of compound Sb2S3 at a pressure of 10**-5 torr. and in argon ambient. Then, their electrical and photoconductive properties were investigated. The Sb2S3 glass-layer showed maximum photosensitivity at the deposition rate of 250\ulcornersec, and Sb2S3 porous layer had mininum dielectric constant of 1.5 at the deposition rate of 0.3 um/sec and argon partial pressure of 0.2torr. Sb2S3 multi-layers were prepared at the different thickness ratio (B/A) to find the proper structural property suited for camera pick-up tube. Here, A is the sum of the thickness of Sb2S3 porous layer and Sb2S3 fine grain layer, and B is the thickness of Sb2S3 fine grain layer. As a result, photosensitivity had a peak value at the thickness ratio (B/A) of 60%.