• 한국표면공학회지
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• 제29권6호
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• pp.862-868
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• 1996

Cadmium sulfide is commonly used as the window material for thin film solar cells, and can be prepared by several techniques such as sputtering, spray pyrolysis, close spaced sublimation (CSS), thermal evaporation, solution growth methods, etc. In this study, CdS films were deposited by thermal evaporation, close spaced sublimation, and solution growth methods, respectively, and the effects of the methods on physical properties of polycrystalline CdS deposited on ITO/glass were investigated. Also, the effects of variously prepared CdS thin films on the physical properties of CdTe deposited on the CdS were investigated. The thickness of polycrystalline CdS films was maintained at $0.3\mu\textrm{m}$ except for the solution grown CdS when $0.2\mu\textrm{m}$ thick CdS was deposited. After the deposition, all the samples were annealed at $400^{\circ}C$ or $500^{\circ}C$ in H2 atmosphere. To investigate physical properties of the deposited and annealed CdS thin films, UV-VIS spectro-photometry, X-ray diffractometry (XRD), and Auger electron spectroscopy (AES), and cross sectional transmission electron microscopy(XTEM) were used to analyze grain size, crystal structure, preferred orientation, optical properties, etc. The annealed CdS showed the bandedge transition at 510nm and the optical transmittance high than 80% for all of the variously deposited films. XRD results showed that CdS thin films variously deposited and annealed had the same hexagonal structures, however, showed different preferred orientations. CSS grown CdS had [103] preferred orientation, thermally evaporated CdS had [002], and CdS grown by the solution growth had no preferred orientation. The largest grain size was obtained for the CSS grown CdS while the least grain size was obtained for the solution grown CdS. Some of the physical properties of CdTe deposited on the CdS thin film such as grain size at the junction and grain orientation were affected by the physical properties of CdS thin films.

• 한국표면공학회지
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• 제47권3호
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• pp.99-103
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• 2014

The encapsulation method of flexible organic light emitting devices (OLEDs) was investigated for the structure of ITO / 2-TNATA / NPB / $Alq_3$ : Rubrene (1 vol.%) / $Alq_3$ / LiF / Al / $Alq_3$ / LiF / Al (OLED #1), on which $SiN_x$ thin film was deposited and metal film was attached to protect the damage of OLED from oxygen and moisture. The $SiN_x$ thin film was deposited by plasma enhanced chemical vapor deposition (PECVD) method using $SiH_4$ of 20 sccm and $N_2$ of 15~35 sccm as reactor gases. The optimum $SiN_x$ deposition condition was found to be 20 sccm $SiH_4$ and 20 sccm $N_2$ from the Ca test of the fabricated $SiN_x$ thin film. The life time of OLED #1, OLED #1 / $SiN_x$ 200 nm, OLED #1 / $SiN_x$ 400 nm and OLED #1 / $SiN_x$ 400 nm / metal film was 7, 12, 25, and 45 hours, respectively. In conclusion, it has been shown that the lifetime of OLEDs can be improved more than 6 times by $SiN_x$ film and a metal film encapsulation.

• 마이크로전자및패키징학회지
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• 제16권2호
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• pp.21-25
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• 2009

The organic-inorganic thin film transistors (OITFTs) with ZnO channel layer and the cross-linked PVP (Poly-4-vinylphenol) gate insulator were fabricated on the patterned ITO gate/glass substrate. ZnO channel layer was deposited by using atomic layer deposition (ALD). In order to improve the electrical properties, $O_2$ plasma treatment onto PVP film was introduced and investigated the effect of the plasma treatments on the electrical properties of the OITFTs. The field effect mobility and sub-threshold slope (SS) values of the OITFT decreased slightly from 0.24 to 0.16 $cm^2/V{\cdot}s$ and from 9.7 to 9.2 V/dec, respectively with increasing RF power from 30 to 50 Watt. The $I_{on/off}$ ratio was about $10^3$ for all samples with $O_2$ plasma treatment.

• 한국재료학회지
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• 제18권10호
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• pp.521-528
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• 2008

We present the structural, optical, and electrical properties of amorphous silicon suboxide (a-$SiO_x$) films grown on indium tin oxide glass substrates with a radio frequency magnetron technique from a polycrystalline silicon oxide target using ambient Ar. For different substrate-target distances (d = 8 cm and 10 cm), the deposition temperature effects were systematically studied. For d = 8cm, oxygen content in a-$SiO_x$ decreased with dissociation of oxygen onto the silicon oxide matrix; temperature increased due to enlargement of kinetic energy. For d = 10 cm, however, the oxygen content had a minimum between $150^{\circ}\;and\;200^{\circ}$. Using simple optical measurements, we can predict a preferred orientation of liquid crystal molecules on a-$SiO_x$ thin film. At higher oxygen content (x > 1.6), liquid crystal molecules on an inorganic liquid crystal alignment layer of a-$SiO_x$ showed homogeneous alignment; however, in the lower case (x < 1.6), liquid crystals showed homeotropic alignment.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2012년도 제43회 하계 정기 학술대회 초록집
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• pp.221-221
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• 2012

Small-molecule organic photovoltaic cells have recently attracted growing attention due to their potential for the low-cost fabrication of flexible and lightweight solar modules. The PVP/Ag nanoparticles were synthesized by the reaction of poly vinylpyrrolidone (PVP) and silver nitrate at $150^{\circ}C$. In the reaction, the size of the nanoparticles was controlled by relative mole fractions between PVP and Ag. The PVP/Ag nanoparticles with various sizes were then spin coated on the patterned ITO glass prior to the deposition of the PEDOT:PSS hole transport layer. The scattering of the incident light caused by these incorporated nanoparticles resulted in an increase in the path length of the light through the active layer and hence the enhancement of the light absorption. This scattering effect increased as the size of the nanoparticles increased, but it was offset by the decrease in total transmittance caused by the non-transparent nanoparticles. As a result, the maximum power conversion efficiency, 0.96% which was the value enhanced by 14% compared to the cell without incorporation of nanoparticles, was obtained when the mole fraction of PVP:Ag was 24:1 and the size of the nanoparticles was 20~40 nm.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2012년도 제43회 하계 정기 학술대회 초록집
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• pp.406-406
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• 2012

ZnO는 큰 여기자 결합 에너지, 낮은 유전 상수, 높은 화학적 안정도를 가지고 있기 때문에 전자소자 및 광소자로 많이 응용되고 있다. 여러 가지 불순물을 주입하여 ZnO의 전기적 및 광학적 성질을 향상시키기 위한 연구가 진행되고 있다. 여러 가지 불순물 중에 Zn와 물리적 및 화학적 성질이 유사한 Cu를 도핑하여 전기화학적성장(electrochemical deposition) 방법으로 ITO가 코팅된 유리 기판 위에 ZnO 박막을 성장하였다. Cu를 도핑하여 ZnO박막을 성장한 결과 구조적으로 ZnO 박막이 나노로드 형태에서 부분적으로 나노세선 또는 나노로드 형태로 변화함을 확인하였다. 광류미네센스 측정 결과는 벌크 ZnO 박막과 비교하여 Cu를 도핑함으로써 ZnO 나노세선이 3.37 eV의 에너지를 가지는 파장의 크기가 줄어들었고 여러 방향으로 ZnO 나노세선이 형성됨을 알 수 있었다. Cu를 도핑함으로써 ZnO 나노세선의 구조적 변화는 크기 않으나 에너지 밴드갭을 변화할 수 있음을 알 수 있었다. ZnO 나노세선의 광학적 성질을 Cu를 도핑하여 변화할 수 있음을 관측하였으며 불순물을 도핑하여 밴드갭을 변화하여 전자소자 및 광소자를 제작하는 기초지식으로 사용할 수 있다.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2012년도 제43회 하계 정기 학술대회 초록집
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• pp.160-160
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• 2012

산화아연, 산화니켈, 산화망간 등 금속산화물은 전기적, 광학적 및 화학적 특성이 우수하여 태양전지, 연료전지, 광촉매, 가스센싱 등 다양한 분야에 폭 넓게 활용되고 있다. 또한, 그 성장방법에 따라 다양한 형태와 크기를 제어할 수 있으며 각각의 응용되는 분야에서 요구되는 나노구조를 최적화할 수 있는 장점을 갖고 있다. 그 중, 전기화학증착법(electrochemical deposition method)은 기존의 제작방법에 비해서 간단한 공정과정과 저온성장이 가능하기 때문에 많이 사용하고 있으며, 씨드(seed)층의 형성을 통해서 원하고자하는 부분에 성장시킬 수 있다. 한편, 나노기술의 발전과 함께 IT기술이 일상생활에 밀접해지면서 구부리거나 휴대 또는 입을 수 있는 다양한 전자 및 광전자 소자의 기술 개발이 활발하게 이루어지고 있는데, 이와 더불어 다양한 금속산화물 여러 가지 플렉서블 기판에서의 나노구조의 성장 및 제어에 대한 연구가 시도되고 있다. 본 연구에서는, 전기화학증착법을 이용하여 전도성 섬유와 ITO/PET 기판을 포함한 다양한 플렉서블 기판에 산화아연, 산화니켈, 산화망간의 나노구조물을 제작하였다. 실험을 위해, 용액의 농도, 시간, 인가전압을 바꿔가면서 성장조건을 달리하여 다양한 형태와 크기의 금속산화물의 나노복합구조를 형성 및 제어를 할 수 있었다. 또한, 스퍼터링 또는 스핀코팅을 이용하여 다양한 유연기판에 씨드층을 형성함으로써 금속산화물 나노구조를 균일하고 조밀하게 성장시킬 수 있었다. 플렉서블 광전소자 응용을 위해 다양한 형태로 제작된 샘플의 결정구조와 형태, 광학적 특성, 표면특성과 같은 물리적 특성을 조사하였다.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2004년도 Asia Display / IMID 04
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• pp.605-608
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• 2004

A novel blue-green emitting aluminum complex was developed by employing 8-hydroxyquinoline as co-ligand for enhancement of electron transport and light emission abilities so that the electroluminescent (EL) devices do not need additional electron transport layer. The aluminum complex (PAlQ) of 8-hydroxyquinoline and ${\alpha}$-pyridoin was synthesized The structure of the PAlQ was elucidated by FT-IR, UV-Vis and XPS. The PAlQ complex showed thermal stability up to 350$^{\circ}C$ under nitrogen flow by TGA. The photoluminescence (PL) was measured from solid film of the PAlQ complex on quartz substrate. The EL device was fabricated by the vacuum deposition. The device having the structure of ITO/TPD/PAlQ/Al was studied, where N,N-bis(3-methylphenyl}-N,N'-diphenyl-benzidine (TPD) was used as a hole transporting layer. The EL device emitted a blue-green light.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2003년도 제5회 학술대회 논문집 일렉트렛트 및 응용기술연구회
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• pp.65-68
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• 2003

Recently, there is a growing concern on the photovoltaic effects using organic materials. This is a phenomena which converts the solar energy into the electrical one. We have fabricated a device structure of ITO/PEDOT:PSS/CuPc/$C_{60}$/BCP/Al. The PEDOT:PSS layer is made by spin coating. and the other organic layers are made by thermal vapor deposition. By measuring the current-voltage characteristics with an illumination of light. we have obtained a value of $V_{oc}$=0.358V and $J_{sc}$=0.338mA/$cm^2$. A fill factor and efficiency are about 0.271 and 0.033%, respectively. A 500W xenon lamp(ORIEL) was used for a light source, and the light intensity illuminated into the device was about 10mW.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2000년도 춘계학술발표대회
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• pp.149-152
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• 2000

GFP는 박막상태에서 쉽게 전자소자로 제작할 수 있으며, 제작된 전자소자는 빛의 여부에 따라 흐르는 전류의 조절이 가능한 광다이오드 특성을 나타내는 것으로 확인되었다. 또한 박막상태에서의 일방향 전자전달 속도와 전자전달 메커니즘이 확인되어, 향후 분자전자소자의 제작시 기반기술로 제공될 수 있을 것으로 사료된다.