• 터널과지하공간
• /
• 제30권3호
• /
• pp.193-213
• /
• 2020

사용후핵연료 심층처분장 처분공에 설치된 압축 벤토나이트 완충재가 처분공 내벽에 형성된 굴착손상영역 불연속면 내로 침투하는 현상을 보다 더 현실적으로 모사할 수 있는 수학적 모델이 개발되었다. 이 모델에서는 압축 벤토나이트의 침투를 평행 평판 암반 절리을 통한 Bingham 유체의 이동으로 가정한다. 개발된 모델에 의해 벤토나이트의 침투현상을 분석한 결과, 암반 절리를 통해 압축 벤토나이트가 침투하는 최대 깊이는 포화 압축 벤토나이트의 팽윤압과 암반 절리의 폭에 비례하며, 압축 벤토나이트의 항복강도에 반비례하였다. 압축 벤토나이트의 점도는 압축 벤토나이트의 침투 속도를 좌우하나, 최대 침투깊이에는 영향을 미치지 않는다.

• 공업화학
• /
• 제18권5호
• /
• pp.506-510
• /
• 2007

전기적 특성을 가지는 4,4',4''-tris(N-(1-naphthyl)-N-phenylamino)-triphenylamine (1-TNATA)가 유기발광소자(OLED)에서 전극으로 사용되는 ITO (Indium Tin Oxide)와 홀 수송층(Hole Transport Layer, HTL) 사이에 박막으로 진공증착되었다. 분자배열이 잘 되어진 1-TNATA의 경우 ITO와 홀 수송층 사이의 계면에서 생기는 전하주입장벽을 줄임으로 소자의 안정성과 효율을 높여준다. 본 연구에서의 라만 스펙트라(Raman spectra) 분석 결과, 증착된 1-TNATA 박막의 열처리와 증착하는 동안 전자기장 처리에 의해서 박막이 집적되고 분자배열이 이루어짐을 확인하였다. 열처리를 한 경우 1-TNATA 박막으로의 전류 흐름이 25% 증가하였다. 또한, $110^{\circ}C$에서 열처리한 1-TNATA 박막으로 제조된 다층유기발광소자의 전원 효율과 발광효율이 향상되었다. 열처리한 박막이 전자기장으로 처리한 박막에 비해 높은 효율을 나타내었다.

• 한국응용과학기술학회지
• /
• 제17권2호
• /
• pp.120-125
• /
• 2000

The tfTZ(4,4',4''-trifluoro-triazine) was used as a hole blocking material for the electroluminescent devices(ELDs) in this study. In general, the holes are outnumbered the electrons in hole transport and emitting layers because the hole transport is more efficient in most organic ELDs. The hole blocking layer are expected to control the excess holes to increase the recombination of holes and electrons and to decrease current density. The former study using the 2,4,6-triphenyl-1,3,5-triazine(TTA) as hole blocking layer showed that the TTA did not form stable films with vapor deposition technique. The tfTZ can generate stable evaporated films, moreover the fluorine group can lower the highest occupied molecular orbital(HOMO) level, which produces the energy barrier for the holes. The tfTZ has high electron affinities according to the data by the Cyclic-Voltammety(CV) method, which is developed for the measurement of HOMO and lowest occupied molecular orbital(LUMO) level of organic thin films. The lowered HOMO level is made the tfTZ to be applied for a hole blocking layer in ELDs. We fabricated multilayer ELDs with a structure of ITO/hole blocking layer(HBL)/hole transporting layer(HTL)/emitting layer/electrode. The hole blocking properties of this devices is confirmed from the lowered current density values compared with that without hole blocking layer.

• 한국진공학회:학술대회논문집
• /
• 한국진공학회 2016년도 제50회 동계 정기학술대회 초록집
• /
• pp.405-405
• /
• 2016

CIGS 박막 태양전지에서 완충층으로 사용되는 ZnS는 단파장 영역에서 높은 투과도와 CIGS 계면과의 좋은 접착을 가지고 친환경적이며 3.74eV의 에너지 밴드갭을 가지고 있기 때문에 CdS를 사용했을 때 보다 더 넓은 에너지 영역의 광자를 p-n 접합 경계 영역으로 통과 시킬 수 있고 Cd-free 물질이라는 점에서 기존의 CdS 완충층의 대체 물질로 각광 받고 있다. 본 연구에서는 CIGS 박막에 화학습식공정 방법을 이용하여 최적화된 ZnS 박막의 증착 조건을 찾기 위해 실험 변수인 시약의 농도, 실험온도, 열처리 조건 등의 다양한 변화를 통해 실험을 진행하였고, 박막의 갈라짐과 pin-hole 현상을 개선하고 균일한 막을 제조하기 위해 구연산 나트륨 농도에 따른 ZnS 박막의 특성을 연구하였다. 본 실험 결과로서 실험변수인 황산아연의 농도 0.15M, 암모니아는 0.3M, 티오요소 1M, 공정 온도 $80^{\circ}C$의 최적화 된 조건에서 가장 좋은 품질의 ZnS 박막을 제조하였지만, ZnS 박막의 열처리 후 산소의 양이 줄어감에 따라 박막의 표면이 갈라지고 pin-hole 현상이 발생하는 것을 확인할 수 있었다. 박막의 품질을 개선하기 위해 구연산 나트륨을 첨가하여 실험한 결과 구연산 나트륨의 0.05M의 농도에서는 박막 표면에 90nm의 갈라짐의 크기와 pin-hole 현상이 남아있는 것을 확인하였고, 농도가 높아질수록 점차 크기가 줄어들면서 0.4M에서는 갈라짐이 거의 없는 표면과 pin-hole 현상도 없어지는 것을 확인하였고, 약 144nm의 박막 두께와 3.8eV의 에너지 밴드갭을 가지고, 약 81%의 높은 광투과율을 갖는 고품질의 ZnS 박막을 제작할 수 있었다.

• 한국재료학회지
• /
• 제21권4호
• /
• pp.192-195
• /
• 2011

The electro-deposition of compound semiconductors has been attracting more attention because of its ability to rapidly deposit nanostructured materials and thin films with controlled morphology, dimensions, and crystallinity in a costeffective manner (1). In particular, low band-gap $A_2B_3$-type chalcogenides, such as $Sb_2Te_3$ and $Bi_2Te_3$, have been extensively studied because of their potential applications in thermoelectric power generator and cooler and phase change memory. Thermoelectric $Sb_xTe_y$ films were potentiostatically electrodeposited in aqueous nitric acid electrolyte solutions containing different ratios of $TeO_2$ to $Sb_2O_3$. The stoichiometric $Sb_xTe_y$ films were obtained at an applied voltage of -0.15V vs. SCE using a solution consisting of 2.4 mM $TeO_2$, 0.8 mM $Sb_2O_3$, 33 mM tartaric acid, and 1M $HNO_3$. The stoichiometric $Sb_xTe_y$ films had the rhombohedral structure with a preferred orientation along the [015] direction. The films featured hole concentration and mobility of $5.8{\times}10^{18}/cm^3$ and $54.8\;cm^2/V{\cdot}s$, respectively. More negative applied potential yielded more Sb content in the deposited $Sb_xTe_y$ films. In addition, the hole concentration and mobility decreased with more negative deposition potential and finally showed insulating property, possibly due to more defect formation. The Seebeck coefficient of as-deposited $Sb_2Te_3$ thin film deposited at -0.15V vs. SCE at room temperature was approximately 118 ${\mu}V/K$ at room temperature, which is similar to bulk counterparts.

• 한국정보디스플레이학회:학술대회논문집
• /
• 한국정보디스플레이학회 2002년도 International Meeting on Information Display
• /
• pp.714-716
• /
• 2002

Indium tin oxide (ITO) was used as the top anode of top emission inverted organic light emitting diodes (TEIOLEDs). TEIOLEDs were fabricated by deposition of an aluminum bottom cathode, an N,N'-diphenyl-N,N'-bis(3-methylphenyl)-1, 1'-diphenyl-4, 4 1'-diamine (TPD) hole transport layer, a tris-8-hydroxyquinoline aluminum ($Alq_3$) emission layer, and an ITO top anode sequentially. ITO was deposited by r.f. magnetron sputtering without $O_2$ flow during the deposition. After the deposition, the deposited ITO layer was kept under oxygen atmosphere for the oxidation. The characteristics of the TEOILED were affected significantly by the post-deposition oxidation condition.

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 2009년도 하계학술대회 논문집
• /
• pp.34-35
• /
• 2009

We have studied the electrical and optical of organic light-emitting diodes depending on hole size of crucible boat using BCP materials. The thickness of TPD, $Alq_3$ and BCP was manufactured 40 nm, 60 nm and 5 nm under a base pressure of $5\times10^{-6}$ Torr using at thermal evaporation, respectively. In order to investigate the optimal surface roughness of BCP, the BCP was thermally evaporated to be 0.8 nun, 1.0 mm, 1.2 mm and 1.5 mm as a hole size of crucible boat, respectively. As the experimental results, we found that the luminous efficiency and the external quantum efficiency of the device is superior to others when hole size of crucible boat using BCP is 1.2 mm. Also, compared to the ones from the devices having the hole size of crucible boat is 1.0 mm and 1.5mm layer, the external quantum efficiency were improved by 2.5 and 2.4 times.

• 한국전기전자재료학회논문지
• /
• 제19권11호
• /
• pp.1037-1043
• /
• 2006

We report the enhancement of hole injection using ozone-treated Ag nanodots dispersed on indium tin oxide anode in $Ir(ppy)_3-doped$ phosphorescent OLED. Phosphorescent OLED fabricated on Ag nanodots dispersed ITO anode showed a lower turn on voltage and higher luminescence than those of OLEDS prepared commercial ITO anode. Synchrotron x-ray scattering examination results showed that the Ag nanodots dispersed on ITO anode is amorphous structure due to low deposition temperature. It was thought that decrease of the energy barrier height as Ag nanodots changed to $AgO_x$ nanodots by surface treatment using ozone for 10 min led to enhancement of hole injection in phosphorescent OLED. Futhermore, efficient hole injection can be explained by increase of contact region between anode material and organic material through introduction of $Ag_2O$ nanodots.

• E2M - 전기 전자와 첨단 소재
• /
• 제10권1호
• /
• pp.8-14
• /
• 1997

The UV/O$_{3}$ dry cleaning has been well known in removing organic molecules. The UV/O$_{3}$ dry cleaning method was performed to clean the Si wafer surfaces and contact holes contaminated by organic molecules such as residual PR. During the cleaning process, the Si surfaces were analyzed with X-ray photoelectron spectroscopy (XPS), atomic force microscope (AFM) and ellipsometer. When the UV/O$_{3}$ dry cleaning at 200'C was performed for 3 minutes, the residual photoresist was almost removed on Si wafer surfaces, but Si surfaces were oxidized. For UV/O$_{3}$ application of contact hole cleaning, the contact string were formed using the equipment of ISRC (Inter-university Semiconductor Research Center). Before Al deposition, UV/O$_{3}$ (at 200.deg. C) dry cleaning was performed for 3 minutes. After metal annealing, the specific contact resistivity was measured. Because UV/O$_{3}$ dry cleaning removed organic contaminants in contact holes, the specific contact resistivity decreased. Each contact hole size was different, but the specific contact resistivities were all much the same. Thus, it is expected that the UV/O$_{3}$ dry cleaning method will be useful method of removal of the organic contaminants at smaller contact hole cleaning.

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 2007년도 추계학술대회 논문집
• /
• pp.29-30
• /
• 2007

In a device structure of ITO/tris(8-hydroxyquinoline) aluminum $(Alq_3)$/Al device, We investigated an the electrical characteristics of Organic Light-Emitting Diodes (OLEDs) depending on the hole-size of boat. The device was manufactured using a thermal evaporation under a base pressure of $5{\times}10^{-6}$ [Torr]. The $Alq_3$ organics were evaporated to be 100 [nm] thick at a deposition rate of $1.5[{\AA}/s]$, and in order to investigate the optimal surface roughness of $Alq_3$, the $Alq_3$ was thermally evaporated to be 0.8 [mm], 1.0 [mm], 1.5 [mm], and 3.0 [mm] as a hole-size of the boat respectively. We found that when the hole-size of the boat is 1.0 [mm], luminance and external quantum efficiency are superior.