• 전자공학회논문지A
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• 제29A권9호
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• pp.36-45
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• 1992

The Modified Multi-Quantum Well(MMQWAl) structures have been grown by Mental-Organic chemical Vapor Deposition(MOCVD) method and stripe type MMQW laser diodes have been investigated. In the case of GaAs/AlGaAs superlattice and quantum well growth by MOCVD, the periodicity, interface abruptess, Al compositional uniformity and layer thickness have been confirmed though the shallow angle lapping technique, double crystal x-ray diffractometry (DCXD) and photoluminescence (PL) measurement. stripe-type MMQW laser diodes have been fabricated using the process technology of photolithography, chemical etching, ohmic contact, back side removing and cleaving. As the result of the electrical and opticalmeasurement of these laser diodes, we have achieved the series resistance of $1[\Omega}~2{\Omega}$ by current-voltage measurements, the threshold current of 200-300mA by currnt-light measurements and the lasing wavelength of 8000-8400$\AA$ by lasing spectrum measurements.

• 한국세라믹학회지
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• 제32권3호
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• pp.349-358
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• 1995

The ceramic composite membrane was synthesized by thermal oxidation after evaporation of Al on the support prepared by slip casting process. Oxidation was performed at $700^{\circ}C$ and 80$0^{\circ}C$ under dry oxygen atmosphere. It was considered as optimum oxidation condition that the membrane showed a knudsen behaviro. A further oxidation resulted in an increase of gas permeability because top layer became densified. Then, a multi-layered composite membrane was synthesized through a sol-gel method, evaporation and thermal oxidation of Al coating processes. While the membrane was thermally stable up to 80$0^{\circ}C$, gas permeability was rapidly decreased even at a slight amount of deposition of Al.

• 한국진공학회지
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• 제2권4호
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• pp.474-479
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• 1993

Submicron contact hole filling with aluminum alloys has been achieved with a multistep metallization method, which utilizes a metal " flow" or self-diffusion process at elevated temperatures after the metal was sputter-deposited. A multi-chamber, modular sputtering system was employed to deposit aluminum alloys and subsequently to anneal the deposited metal films under vacuum at high temperatures. The film were deposited on 200 mm wafers with planar, dc magnetron sputtering sources without anysubstrate bias. The basic process steps studied for the multistep metallization include an initial layer deposition at low temperatures less than $100^{\circ}C$, and an annealin gstep at elevated temperatures, between 450 and $550^{\circ}C$. The degree of planarization or step coverage was dependent strongly upon the temperature and time of the flow step and complete filling of the submicron contacts with aluminum alloys was achieved. Responsible mechanisms for the enhancement in step coverge and factros determining uniform and reproducible flow of aluminum alloys during the high temperauture step are discussed.discussed.

• 반도체디스플레이기술학회지
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• 제5권2호
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• pp.1-5
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• 2006

The GaN thin film on the 8 periods InGaN/GaN multi-quantum well structure was grown on the sapphire substrate using metal-organic chemical vapor deposition. The nano-scaled triangular-lattice holes with the diameter of 150 nm were patterned on a polymethylmethacrylate blocking film using an electron beam nano-lithography system. The thin slab and two-dimensional photonic crystals with the thickness of 28 nm were fabricated on the GaN layer for the blue light diffraction sources. The photonic crystal with the lattice parameter of 460 nm enhances spectral intensity of photoluminescence indicating that the photonic crystals provides the source of nano-diffraction for the blue light of the 450-nm wavelength.

• 한국표면공학회:학술대회논문집
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• 한국표면공학회 2018년도 춘계학술대회 논문집
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• pp.42.1-42.1
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• 2018

정전용량방식 터치스크린패널은 모바일에서 차량용 디스플레이에 이르기까지 휴대용 전자장치를 위한 직관적인 사용자 인터페이스 덕분에 최근 몇 년간 관심이 집중 되었다. 본 연구에서는 우수한 성형성과 정확성 및 고감도 터치패널 제작을 위해 Ionized Physical Vapor Deposition (IPVD)시스템을 이용하여 멀티레이어(Oxide/Metal/Oxide)의 투명전극을 형성 하였다. 멀티레이어 전극은 5.1 ohm/sq의 면저항과 89.5%의 투과율을 나타내며, 높은 신뢰성 및 접촉력의 특성을 나타내는 것을 확인 하였다. 이를 통해, 기존의 패턴크기보다 작은 3.8mm pitch 패턴의 15인치 GFF타입 터치패널을 성공적으로 제작 하였으며, 터치센서는 우수한 선형성, 정확성 및 고감도 스타일러스펜 (직경=1mm)의 멀티터치를 구현 하였다.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2013년도 제44회 동계 정기학술대회 초록집
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• pp.235-235
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• 2013

We reported on the characteristics of organic solar cells (OSCs) fabricated on $HNO_3$-treated multilayer graphene (MLG) transparent electrodes. MLG electrodes were prepared using a chemical vapor deposition and a multi-transfer process. Compared to organic solar cells (OSCs) on the ITO electrodes had a fill factor of 65.97%, and a power conversion efficiency (PCE) of 3.364%, OSCs on the MLG (three-layer graphene) electrodes with sheet resistance of $274{\pm}1{\Omega}$/square and transparency of 92.1% had a fill factor of 43.46%, and a power conversion efficiency (PCE) of 2.019%. However, OSCs on the HNO3-treated MLG electrodes with lower sheet resistance of $119{\pm}1{\Omega}$/square had a fill factor of 57.54%, and a PCE of 2.861%. The results would provide a promising method to improve the performance of large-area OSCs based on MLG electrodes.

• 마이크로전자및패키징학회지
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• 제26권4호
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• pp.107-111
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• 2019

We report the fabrication of a CdS/CuInGaSe (CdS/CIGS) structure with carbon nanotubes and its application as a photocathode for photoelectrochemical water splitting. CIGS thin films were fabricated using co-evaporation by RF magnetron sputtering, while CdS was fabricated by chemical bath deposition. Spray coated multi-wall carbon nanotube (CNT) film on CdS/CIGS thin film was investigated as a photocathode. The CNT-coated CdS/CIGS showed superior photocurrent density and exhibited improved photostability.

• Journal of Ceramic Processing Research
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• 제19권6호
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• pp.525-529
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• 2018

The antireflective (AR) coated poly methyl methacrylate (PMMA) substrate was deposited by atomic layer deposition (ALD) on a self-assembled monolayer (SAM) to improve hydrophobicity and mechano-chemical properties of organic thin films. The water contact angles (WCA) were tested to characterize the surface wettability of SAM octadecyltrichlorosilane (OTS) films. Results showed that a contact angle of $105.9^{\circ}$ was obtained for the SAM films with an annealing process, and the highest WCA of $120^{\circ}$ was achieved for the films prepared by the SAM and ALD multi-process. The surface morphology of the SAM films with different assembly times and varying number of ALD cycles was obtained by atomic force microscopy (AFM). The maximum light transmittance for the SAM films on the PMMA substrate reached 99.9% at a wavelength of 450 nm. It was found that the SAM surfaces were not affected at all by the ALD process.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2011년도 제40회 동계학술대회 초록집
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• pp.185-185
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• 2011

ZnTe semiconductor is very attractive materials for optoelectronic devices in the visible green spectral region because of it has direct bandgap of 2.26 eV. The prototypes of ZnTe light emitting diodes (LEDs) have been reported [1], showing that their green emission peak closely matches the most sensitive region of the human eye. Another application to photovoltaics proved that ZnTe is useful for the production of high-efficiency multi-junction solar cells [2,3]. By using the pulse laser deposition system, ZnTe thin films were deposited on ZnO thin layer, which is grown on (0001) Al2O3substrates. To produce the plasma plume from an ablated ZnO and ZnTe target, a pulsed (10 Hz) YGA:Nd laser with energy density of 95 mJ/$cm^2$ and wavelength of 266 nm by a nonlinear fourth harmonic generator was used. The laser spot focused on the surface of the ZnO and ZnTe target by using an optical lens was approximately 1 mm2. The base pressure of the chamber was kept at a pressure around $10^{-6}$ Torr by using a turbo molecular pump. The oxygen gas flow was controlled around 3 sccm by using a mass flow controller system. During the ZnTe deposition, the substrate temperature was $400^{\circ}C$ and the ambient gas pressure was $10^{-2}$ Torr. The structural properties of the samples were analyzed by XRD measurement. The optical properties were investigated by using the photoluminescence spectra obtained with a 325 nm wavelength He-Cd laser. The film surface and carrier concentration were analyzed by an atomic force microscope and Hall measurement system.

• 한국재료학회지
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• 제19권1호
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• pp.50-53
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• 2009

Multi-walled carbon nanotubes (MWNTs) were synthesized on different substrates (bare Si and $SiO_2$/Si substrate) to investigate dye-sensitized solar cell (DSSC) applications as counter electrode materials. The synthesis of MWNTs samples used identical conditions of a Fe catalyst created by thermal chemical vapor deposition at $900^{\circ}C$. It was found that the diameter of the MWNTs on the Si substrate sample is approximately $5{\sim}10nm$ larger than that of a $SiO_2$/Si substrate sample. Moreover, MWNTs on a Si substrate sample were well-crystallized in terms of their Raman spectrum. In addition, the MWNTs on Si substrate sample show an enhanced redox reaction, as observed through a smaller interface resistance and faster reaction rates in the EIS spectrum. The results show that DSSCs with a MWNT counter electrode on a bare Si substrate sample demonstrate energy conversion efficiency in excess of 1.4 %.