• 한국진공학회:학술대회논문집
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• 한국진공학회 2006년도 제31회 학술논문발표회 초록집
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• pp.173-173
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• 2006

• 한국전기전자재료학회논문지
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• 제17권10호
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• pp.1100-1106
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• 2004

In this paper, we intend to make fringe-field switching (FFS) mode cell by the ion beam (IB) alignment method on the a-C：H thin film, to analyze electro-optical characteristics in this cell. We studied on the suitable inorganic thin film for fringe-field switching (FFS) cell and the aligning capabilities of nematic liquid crystal (NLC) using the alignment material of a-C：H thin film as working gas at 30 W rf bias condition. A high pretilt angle of about 5 $^{\circ}C$ by ion beam (IB) exposure on the a-C：H thin film surface was measured. Consequently, the high pretilt angle and the good thermal stability of LC alignment by the IB alignment method on the a-C：H thin film surface as working gas at 30 W rf bias condition can be achieved. An excellent voltage-transmittance (V -T) and response time curve of the IE-aligned FFS-LCD was observed with oblique IB exposure on the a-C：H thin films. Also, AC V-T hysteresis characteristics of the IB-aligned FFS-LCD with IE exposure on the a-C：H thin films is almost the same as that of the rubbing-aligned FFS cell on a polyimide (PI) surface.

• 폴리머
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• 제38권5호
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• pp.573-579
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• 2014

탄소나노튜브(CNT), 불소계 아크릴레이트 2,2,2-trifluoroethylmethacrylate(3FMA) 및 유-무기 조성비와 같은 합성조건을 달리하여 제조된 자외선 경화형 유-무기 하이브리드 코팅 막의 표면특성 및 내오존성에 대해 연구하였다. 코팅 막은 금속 알콕사이드 전구체인 tetraethoxysilane(TEOS)와 실란 커플링제인 methacryloyloxypropyltrimethoxysilane (MPTMS)로 구성된 유-무기 혼성 용액에 탄소나노튜브 및 3FMA와 자외선 경화를 위한 유기물을 첨가하여 제조된 코팅제를 자외선 경화시켜 제조하였다. 제조된 코팅 막의 내오존성 및 기재와의 접착력은 TEOS, 3FMA 및 CNT의 함량에 크게 영향을 받는다는 것을 확인하였다. 특히, 탄소나노튜브가 첨가된 코팅 막은 우수한 내오존성 및 접착력 뿐만 아니라 높은 표면경도를 나타내었다. TEOS의 경우, 함량이 증가할수록 표면경도 및 내오존성은 향상되었지만, 기재와의 접착력은 감소되었다. 불소아크릴레이트 3FMA의 경우, 함량이 증가할수록 내오존성은 향상되었지만 표면경도는 감소하였다.

• Journal of the Optical Society of Korea
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• 제10권1호
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• pp.1-10
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• 2006

Optical transparency and high diffraction efficiency are two essential factors for high performance of the photopolymer. Optical transparency mainly depends on the miscibility between polymer binder and photopolymerized polymer, while diffraction efficiency depends on the refractive index modulation between polymer binder and photopolymerized polymer. For most of organic materials, the large refractive index difference between two polymers accompanies large structural difference that leads to the poor miscibility and thus poor optical quality via light scattering. Therefore, it is difficult to design a high-performance photopolymer satisfying both requirements. In this work, first, we prepared a new phase-stable photopolymer (PMMA) with large refractive index modulation and investigated the optical properties. Our photopolymer is based on modified poly (methyl methacrylate) as a polymer binder, acryl amide as a photopolymerizable monomer, triethanolamine as initiator, and yellow eosin as a photosensitizer at 532 nm. Diffraction efficiency over 85% and optical transmittance over 90% were obtained for the photopolymer. Second, Organic-inorganic nanocomposite films were prepared by dispersing an aromatic methacrylic monomer and a photo- initiator in organic-inorganic hybrid sol-gel matrices. The film properties could be controlled by optimizing the content of an organically modified silica precursor (TSPEG) in the sol-gel matrices. The photopolymer film modified with the organic chain (TSPEG) showed high diffraction efficiency (> 90%) under an optimized condition. High diffraction efficiency could be ascribed to the fast diffusion and efficient polymerization of monomers under interference light to generate refractive index modulation. The TSPEG modified photopolymer film could be successfully used for holographic memory.

• 폴리머
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• 제31권2호
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• pp.111-116
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• 2007

폴리우레탄 변형 아크릴레이트(PUA)/실리카 하이브리드 필름은 자외선 경화에 의해 제조되었고, 필름의 표면물성은 경도시험과 접착력 테스트를 통해 분석되었다. 이들 필름은 유기, 무기함량을 mole비로 조성하여 실험하였으며, 무기조성은 실리카 입자의 함량을 기준으로 설정하였다. 필름 층 내의 실리카 입자는 함량에 따라 혹은 분산정도에 따라 내스크래치성이나 필름자체 경도 등의 물성이 많은 차이를 보였는데, 이는 PUA필름 층 내의 실리카 입자들이 균일하게 분포되어 가교결합되어 있었기 때문이다.

• 한국재료학회지
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• 제28권12호
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• pp.748-757
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• 2018

Inorganic semiconductor compounds, e.g., CIGS and CZTS, are promising materials for thin film solar cells because of their high light absorption coefficient and stability. Research on thin film solar cells using this compound has made remarkable progress in the last two decades. Vacuum-based processes, e.g., co-evaporation and sputtering, are well established to obtain high-efficiency CIGS and/or CZTS thin film solar cells with over 20 % of power conversion. However, because the vacuum-based processes need high cost equipment, they pose technological barriers to producing low-cost and large area photovoltaic cells. Recently, non-vacuum based processes, for example the solution/nanoparticle precursor process, the electrodeposition method, or the polymer-capped precursors process, have been intensively studied to reduce capital expenditure. Lately, over 17 % of energy conversion efficiency has been reported by solution precursors methods in CIGS solar cells. This article reviews the status of non-vacuum techniques that are used to fabricate CIGS and CZTS thin films solar cells.

• The Korean Journal of Ceramics
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• 제6권2호
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• pp.134-137
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• 2000

Zirconia films stabilized b $Y_2O_3$, YSZ, films were deposition by metal organic chemical vapor deposition (MOCVD) onto various kind of substrates. $Y_2O_3$, $ZrO_2$and the mixtures of these two were deposited and characterized. The deposition rate, the film composition and the structure could be systematically varied through the $Y(C_{11}H_{19}O_2)_3$, Zr(O.t-$C_H_9)_4$source gas ratios and the deposition temperature. The Y/Zr ratio in YSZ film could be adjusted by controlling the ratio of $Y(C_{11}H_{19}O_2)_3$, Zr(O.t-$C_4H_9)_4$partial pressures. This is because the ratios of the deposition rates of Y and Zr atoms in $Y_2O_3$and $ZrO_2$films to those in YSZ films, Ф, are constant irrespective of the input gas concentration. However, the Y/Zr ratio was found to be smaller than that estimated based on the deposition rates of un-mixed $Y_2O_3$and $ZrO_2$films. This is because the Фs of Y and Zr atoms are not equal. The activation energy of $Y_2O_3$component in YSZ films was similar to that of $ZrO_2$component in YSZ films. These YSZ values were more than 4 times larger than those of un-mixed $Y_2O_3$or $ZrO_2$films.

• 멤브레인
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• 제12권4호
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• pp.240-246
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• 2002

방사선과의 상호작용에 의하여 섬광이 발생하는 무기형광체(inorganic fluor)인 cerium activated yttrium silicate(CAYS)를 폴리설폰 고분자막에 함침시킴으로써, 형광 용액의 도움 없이 방사능 오염도를 측정할 수 있는 새로운 측정막을 제조하였다. 막의 제조는 두 가지 공정으로 나누어진다. 우선 고분자와 용매의 균일한 1차 제막용액을 유리판 위에 제막 후 용매증발을 통해 폴리설폰 고분자막이 생성되도록 하였다. 고형화된 폴리설폰 필름 표면에 CAYS가 분산된 고분자 제막용액을 2차로 도포시킨 후, 비용매 욕조에 침지시키는 상전환 공정을 이용하거나 용매의 증발을 통한 유리화에 의해 2차 용액의 고형화를 유도함으로써 함침막을 제조하였다. 이렇게 제조된 막의 형상은 치밀한 구조를 지니는 고분자 지지체와 이에 완전히 고착된 CAYS함침막의 이중구조를 지니게되며, 지지체 부분은 막의 안정성을 2차 제막에서 생성된 부분은 기능성의 향상을 이룰 수 있는 구조적 특성을 지닌다. 제조된 함침막에 방사성핵종을 직접 도포하여 방사성핵종의 탐지 특성을 측정하였을 때 효율적인 탐지 특성을 지니는 것으로 확인되었다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1998년도 하계학술대회 논문집 D
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• pp.1370-1372
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• 1998

Boron doped CdS films were prepared by CBD(Chemical Bath Deposition) method using boric acid ($B_3HO_3$) as donor dopant source, and their properties were investigated. As-grown CdS films were highly adherent and specularly reflective. Boron doped CdS film which was fabricated under the condition of 0.01 $B_3HO_3/Cd(Ac)_2$ mole ratio, exhibited the lowest resistivity of $2{\Omega}cm$ and the highest optical bandgap of 2.41eV. Also, CdS/CdTe solar cells were fabricated with various doping concentration of CdS films. Using optimized CdS film as the window layer of CdS/CdTe solar cell, the characteristics of the cell were improved. ( $V_{oc}$=610mV, $J_{sc}$=37.5mA/cm, FF=0.4, $\eta$=9.1% )

• 마이크로전자및패키징학회지
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• 제16권4호
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• pp.17-22
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• 2009

Two different organic-inorganic hybrid thin film transistors (OITFTs) with the structures of glass/ITO/ZnO/PMMA/Al (staggered structure) and glass/ITO/PMMA/ZnO/Al (inverted staggered structure), were fabricated and their electrical and structural properties were compared. The ZnO thin films used as active channel layers were deposited by the atomic layer deposition (ALD) method at a temperature of $100^{\circ}C$. To investigate the effect of the substrates on their properties, the ZnO films were deposited on bare glass, PMMA/glass and ITO/glass substrates and their crystal properties and surface morphologies were analyzed. The structural properties of the ZnO films varied with the substrate conditions. The ZnO film deposited on the ITO/glass substrate showed better crystallinity and morphologies, such as a higher preferred c-axis orientation, lower FWHM value and larger particle size compared with the one deposited on the PMMA/glass substrate. The field effect mobility ($\mu$), threshold voltage ($V_T$) and $I_{on/off}$ switching ratio for the OITFT with the staggered structure were about $0.61\;cm^2/V{\cdot}s$, 5.5 V and $10^2$, whereas those of the OITFT with the inverted staggered structure were found to be $0.31\;cm^2/V{\cdot}s$, 6.8 V and 10, respectively. The improved electrical properties for the staggered OITFTs may originate from the improved crystal properties and larger particle size of the ZnO active layer.