• 한국진공학회:학술대회논문집
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• 한국진공학회 2011년도 제40회 동계학술대회 초록집
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• pp.337-337
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• 2011

The elecronic absorption and surface morphology evolution of two types of molecular double layer thin films, copper phthalocyanine(CuPc) layer deposited on top of chloro[subphtalocyaninato]boron(III) (SubPc) layer, denoted as SubPc/CuPc, and vice versa, at various thicknesses were invertigated using ultraviolet(UV)-visible spectroscopy and atomic force microscopy (AFM). Both types of double layer structures showed similar broadened absorption patterns in UV-visible region which were well consistent with fitted spectra by a simple linear combination of single layer absorption spectra of two materials. In contrast, the surface morphology of double layer structures was dependent on the order of deposition. For CuPc/SubPc structures, the surface morphology was characterized by elongated grains, characteristic of SubPc thin films, indicating the morphological influence of underlying CuPc layer on subsequent SubPc layer was not large. For SubPc/CuPc structures, however, the underlying SubPc layer acted as a morphological template for the subsequently deposited CuPc layer. It was also observed that the grain size of CuPc layer varied by the thickness of underlying SubPc layer.

• Bulletin of the Korean Chemical Society
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• 제32권3호
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• pp.943-946
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• 2011

The electronic absorption and surface morphology evolution of two types of molecular double layer thin films, copper phthalocyanine (CuPc) layer deposited on chloro[subphthalocyaninato]boron(III) (SubPc) layer, denoted as SubPc/CuPc, and vice versa, with various thicknesses were investigated using ultraviolet (UV)-visible spectroscopy and atomic force microscopy (AFM). Both types of double layer structures showed similar broadened absorption patterns in the UV-visible region that were consistent with the fitted spectra following simple linear combination of the single layer absorption spectra of the two materials. In contrast, the surface morphology of double layer structures was dependent on the order of deposition. For the CuPc/SubPc structures, surface morphology was characterized by elongated grains, which are characteristic of SubPc thin films, indicating that the morphological influence of the underlying CuPc layer on the subsequent SubPc layer was not large. For the SubPc/CuPc structures, however, the underlying SubPc layer acted as a morphological template for the subsequently deposited CuPc layer. It was also observed that the grain size of the CuPc layer varied according to the thickness of the underlying SubPc layer.

• 대한화학회지
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• 제67권1호
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• pp.33-41
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• 2023

Nanocrystallne WO₃ and MoO₃ with several different sizes and crystal structures were prepared by simple acid precipitation and subsequent heat treatment. The photochromic (PC) properties of these samples were comparatively investigated in powder state by monitoring diffuse reflectance spectral changes after bandgap irradiation. The PC effect of hexagonal WO₃ and monoclinic WO₃ strongly depended upon crystallite size rather than crystal structure. The smaller the crystallite size, the better the PC effect. However, orthorhombic WO·H₂O and MoO₃ having hexagonal and orthorhombic structures did not follow this trend. One consistent result for all WO₃ and MoO₃ samples is that the heat treatment in air, which changes crystallinity, whether it changes the crystal structure or only the crystallite size, reduces the PC effect. Since the thermal treatment reduces the surface oxygen defect sites, we believe that the PC effect of WO₃ and MoO₃ depends critically on the surface oxygen defect sites that serve as deep trap sites for photogenerated electrons and oxygen radical holes. We also found that the proton insertion claimed by double charge injection model is not critical for the PC effect.

• Transactions on Electrical and Electronic Materials
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• 제8권4호
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• pp.174-177
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• 2007

We fabricated organic field-effect transistors (OFETs) based a fluorinated copper phthalocyanine ($F_{16}CuPC$) and copper phthalocyanine (CuPc) as an active layer. And we observed the surface morphology of the $F_{16}CuPC$ thin film. The $F_{16}CuPC$ thin film thickness was 40 nm, and the channel length was $50{\mu}m$, channel width was 3 mm. And we also fabricated the $F_{16}CuPc/CuPc$ double layer FET and with different $F_{16}CuPc$ film thickness devices. We observed the typical current-voltage (I-V) characteristics and capacitance-voltage (C-V) in $F_{16}CuPc$ FET and we calculated the effective mobility. From the double layer FET devices, we observed the higher drain current more than single layer FET devices.

• 멤브레인
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• 제26권2호
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• pp.126-134
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• 2016

바이오 가스로부터 바이오 메탄을 생산하기 위해 물리흡수제 특성평가 및 $CO_2/CH_4$흡수 연구를 진행하였고, poly-propylene(PP) 중공사막 막접촉기에 적용해보았다. 물리흡수제 중 propylene carbonate (PC)는 PP 중공사막과 가장 높은 $58.3^{\circ}$ 접촉각을 보였고, 5 wt% PC를 물과 혼합할 경우 $90^{\circ}$ 이상의 접촉각이 관찰되었다. 또한 $CO_2$ 흡수실험에서 PC/물 혼합 흡수제는 물 흡수량(0.121 mmol/g) 보다 높은 0.148-0.157 mmol/g의 흡수량을 보이며, 막접촉기에 가장 적합한 물리흡수제로 선정되었다. PC/물 혼합 흡수제를 막접촉기에 적용 후 얻어진 $CO_2$ 제거율(98.0-97.8%)과 $CH_4$ 순도(98.5-98.3%)는 바이오 메탄으로서 매우 높은 가능성을 보여주었다. 하지만 PC/물 혼합 흡수제의 경우에는 물 흡수제와 비교하여 성능 변화가 매우 미비하였다. 이는 물보다 우수한 PC 흡수능과 함께 그에 따른 막접촉기 탈기 막 모듈 및 시스템 개선과 공급 유량 조절을 통해 $CH_4$ 손실 최소화 등 공정 최적화가 필요한 것으로 분석된다.

• Journal of information and communication convergence engineering
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• 제13권4호
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• pp.257-263
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• 2015

In this study, organic field-effect transistors (OFETs) using a copper phthalocyanine (CuPc) material as an active layer and SiO₂ as a gate insulator were fabricated with varying active layer thicknesses and channel lengths. Further, using a thermal evaporation method in a high-vacuum system, we fabricated a CuPc FET device of the top-contact type and used Au materials for the source and drain electrodes. In order to discuss the channel formation and FET characteristics, we observed the typical current-voltage characteristics and calculated the threshold voltage of the CuPc FET device. We also found that the capacitance reached approximately 97 pF at a negative applied voltage and increased upon the accumulation of carriers at the interface of the metal and the CuPc material. We observed the typical behavior of a FET when used as an n-channel FET. Moreover, we calculated the threshold voltage to be about 15-20 V at V_DS = -80 V.

• Transactions on Electrical and Electronic Materials
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• 제6권3호
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• pp.115-118
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• 2005

Organic photovoltaic properties were studied in $CuPc/C_{60}$ and $ZnPc/C_{60}$ heterojunction structure by varying the organic layer thicknesses. Current density-voltage characteristics of organic photovoltaic cells were measured using Keithley 236 source-measure unit and a 500 W xenon lamp (ORIEL 66021) for a light source. From the analyses of current-voltage characteristics such as short-circuit current density, open-circuit voltage and power conversion efficiency, optimum thickness of the organic layer were obtained.

• Bulletin of the Korean Chemical Society
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• 제29권12호
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• pp.2533-2536
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• 2008

• Advances in concrete construction
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• 제10권3호
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• pp.221-236
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• 2020

To reduce the CO₂ emissions associated with the manufacture of portland cement (PC), an efficient alternative like an alkali-activated binder (AAB) is the requirement of the industry. To promote the use of AAB in construction activities, a practically implementable mix proportion is required. Owing to the several raw ingredients of AAB concrete and their associated uncertainties, partial replacement of PC by AAB may be adopted instead of complete replacement as per industrial requirements. Hence, the present study aims to determine an optimal proportion for partial replacement of PC with AAB and recommend a technique for it based on site conditions. Three modes of partial replacement are followed: combining all the dry ingredients for AAB and PC followed by the addition of the requisite liquids (PAM); combining the PC and the AAB concrete in two horizontal layers (PAH); and two vertical layers (PAV). 28-day old specimens are exposed to 10% v/v solutions of HCl, H₂SO₄, and HNO₃ to evaluate changes in mechanical, physical, and microstructural characteristics through compressive strength, corrosion depth, and microscopy. Based on deterioration in strength and integrity, PAH or PAV can be adopted in absence of acid attack, whereas PAM is recommended in presence of acid attack.

• 한국진공학회:학술대회논문집
• /
• 한국진공학회 2011년도 제40회 동계학술대회 초록집
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• pp.336-336
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• 2011

Over the past decades, organic semiconductors have been investigated intensely for their potential in a wide range of optoelectronic device applications since the organic materials have advantages for very light, flexible and low cost device fabrications. In this study, we fabricated small-molecule organic solar cells (OSCs) based on chloro[subphthalocyaninato]boron(III) (SubPc) as an electron donor and $C_{60}$ as an electron acceptor material. Recently SubPc, a cone-shaped molecule with $14{\pi}$-electrons in its aromatic system, has attracted growing attention in small-molecule OSC applications as an electron-donating material for its greater open-circuit voltage (VOC), extinction coefficient and dielectric constant compared to conventional planar metal phthalocyanines. In spite of the power conversion efficiency (PCE) enhancement of small-molecule OSC using SubPc and $C_{60}$, however, the study on the interface between donor-acceptor heterojunction of this system is limited. In this work, SubPc thin films at various thicknesses were deposited by organic molecular beam deposition (OMBD) and the evolution of surface morphology was observed using atomic force microscopy (AFM) and field emission scanning electron microscopy (FE-SEM). We also investigated the influence of film thickness and surface morphology on the PCE of small-molecule OSC devices.