• 마이크로전자및패키징학회지
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• 제27권1호
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• pp.31-35
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• 2020

원자층 증착법(ALD: atomic layer deposition)으로 성장된 ZnO n-type 산화물반도체를 이용하여 three terminal memristor (memtransistor) 소자를 제작하여 습도에 따른 그 특성을 관찰하였다. 40 nm 두께의 ZnO 박막을 이용하여 channel width 70 ㎛, length 5 ㎛, back gate 구조의 memtransistor 소자를 제작하여 습도에 (40%, 50%, 60%, 70%) 따른 gate tunable memristive 특성변화를 관찰하였다. 습도가 높아질수록 electron mobility와 gate controllability가 감소하여 수소도핑효과에 의한 carrier 농도가 증가하는 거동의 output curve가 관찰되었다. 60%, 70%의 습도에서 memristive 거동이 관찰되었으며 습도가 높아질수록 on/off ratio는 증가하는 반면 gate controllability가 감소하였다. 60% 습도에서 가장 우수한 특성의 gate tunable memristive 특성을 얻을 수 있었다.

• 한국수소및신에너지학회논문집
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• 제35권1호
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• pp.40-47
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• 2024

Ammonia is drawing attention as carbon free fuel due to its ease of storage and transportation compared to hydrogen. This study suggests ammonia fueled solid oxide fuel cell (SOFC) system with electrochemical hydrogen compressor (EHC)-based recirculation. Performance of electrochemical hydrogen pump is based on the experimental data under varying hydrogen and nitrogen concentration. As a result, the suggested system shows 62.04% net electrical efficiency. The efficiency is 10.33% point higher compared to simple standalone SOFC system (51.71%), but 0.02% point lower compared to blower-based recirculation system (62.06%). Further improvement in the EHC-based SOFC recirculation system can be achieved with EHC performance improvement.

• 공업화학전망
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• 제24권4호
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• pp.22-35
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• 2021

현재 수소전기차는 승용 및 상용 등 다양한 모빌리티 분야에서 전 세계적으로 이슈가 되고 있다. 환경규제 강화, 신기후체제 출범 등의 변화의 물결에 따라 자동차산업의 패러다임이 친환경으로 전환되고 있으며, 세계적으로 관련 기술 개발 및 보급을 위한 확대 정책이 발표되고 있다. 1990년 초 수소전기차(Fuel Cell Electric Vehicle, FCEV) 기술 개발이 진행되어 1994년 독일 다임러사가 세계 최초로 NECAR1을 개발하였다. 이후 많은 완성차가 상용화를 위해 기술개발이 진행되었으며, 2013년 국내 현대차가 세계최초로 양산차인 투싼 ix 수소전기차를 출시하였다. 1년 이후 다시 일본 도요타에서 세계 최초로 전용 차체를 적용한 미라이 수소전기차가 출시되면서 초기시장이 형성되었으며, 이후 현대차는 NEXO를 2018년에 발표하였다. 전 세계적으로 가장 많이 팔린 수소전기차에 해당된다. 2021년 미라이 2세대가 더욱 진보된 기술을 바탕으로 출시되었으며, 국내 현대차에서도 2세대 수소전기차 출시를 앞두고 있다. 또한 수소승용차 뿐만 아니라 수소상용차 시장이 뜨겁게 부각되고 있으며, 각국에서 수소상용차 기술개발을 진행하고 있다. 본 기획특집에서는 각국의 수소전기차 기술개발 및 보급 정책을 소개하고 국내 기술개발 및 보급 정책의 타당성을 확인하고자 하였다.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2005년도 International Meeting on Information Displayvol.II
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• pp.1103-1107
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• 2005

Single-crystal silicon thin films on glass (SOG) and on fused-quartz (SOQ) were prepared using wafer bonding and hydrogen-induced layer transfer. Thinfilm transistors (TFTs) were subsequently fabricated. The high-temperature processed SOQ TFTs show better device performance than the low-temperature processed SOG TFTs. Tensile and compressive strain was measured respectively on SOQ and SOG. Consistent with the tensile strain, enhanced electron effective mobility was measured on the SOQ TFTs.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2002년도 하계종합학술대회 논문집(2)
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• pp.213-216
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• 2002

A double-heterostructure AIGaAs/GaAs PHEMT (Pseudomorphic High Electron Mobility Transistor) using digital recess has been successfully realized. Futhermore, the differences of gm,nax, fT, fmax between two samples are as low as 0.62%, 1.58% and 2.56 % respectively. Experimental results are presented demonstrating the etch rate and Process invariability with respect to hydrogen peroxide and acid exposure times with uniformity among devices on a sample.

• 공업화학
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• 제10권5호
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• pp.743-747
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• 1999

비상용성인 polystyrene(PS)와 polymethacrylate(PMA)의 블렌드에서 분자간 수소결합이 가능하도록 구성고분자를 변성하였다. 공중합을 통해 hydroxystyrene 함량이 몰분율로 각각 7%, 10%, 18% 도입된 poly(styrene-co-4-hydroxystyrene) (modified polystyrene, MPS)을 합성하여 블렌드의 상용성 변화를 살펴보았다. 또한 PMA의 측쇄의 크기가 분자간 수소결합 형성에 미치는 영향을 조사하기 위하여 각각 methyl기, butyl기, hexyl기, ethylhexyl기의 측쇄를 갖는 PMA를 선정하였다. 그 결과 수산기의 함량이 증가함에 따라 분자간 수소결합 형성이 증가하였다. PMA의 측쇄의 크기에 따라 수소결합 형성 정도가 영향을 받아 상용성에 큰 차이가 나타남을 온도변화에 따른 상변화 거동을 통하여 확인하였다. 측쇄의 크기가 증가됨에 따라 입체장애 효과와 증가된 사슬의 운동성 때문에 분자간 수소결합의 형성 및 수소 결합력은 크게 감소하였다.

• 한국표면공학회지
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• 제51권2호
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• pp.116-125
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• 2018

Aluminum-doped zinc oxide (AZO) is a commonly used material for the front contact layer of chalcopyrite $CuInGaSe_2$ (CIGS) based thin film solar cells since it satisfies the requisite optical and electrical properties with low cost and abundant elemental availability. Low-resistivity and high-transmission front contacts have been developed for high-performance CIGS solar cells, and nearly meet the required performance. However, the durability of the cell especially for the corrosion resistance of AZO films has not been studied intensively. In this work, AZO films were prepared on Corning glass 7059 substrates by radio frequency magnetron sputtering depending on the hydrogen content. The electrical and optical properties and electrochemical corrosion resistance of the AZO films were evaluated as a function of the hydrogen content. With increasing hydrogen content to 6 wt%, the crystallinity, crystal size, and surface roughness of the films increased, and the resistivity decreased with increased carrier concentration, Hall mobility, oxygen vacancies, and $Zn(OH)_2$ binding on the AZO surface. At a hydrogen content of 6 wt%, the corrosion resistance was also relatively high with less columnar morphology, shallow pore channels, and lower grain boundary angles.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2009년도 9th International Meeting on Information Display
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• pp.1608-1611
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• 2009

Here the hydrogen passivation treatment has been adopted to enhance the performance of poly-Si crystallized by YAG laser annealing (LA poly-Si). We have investigated the effects of passivation time, passivation power and passivation temperature on the hall mobility of the LA poly-Si and analyzed the mechanism of the hydrogen passivation preliminary. It has been found that the quality of the poly-Si annealed by YAG laser could be improved after proper hydrogen plasma treatment.

• 대한기계학회논문집B
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• 제25권9호
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• pp.1175-1182
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• 2001

Chemical compositions of polydisperse SiO$_2$/TiO$_2$multicomponent aggregates were measured for different heights from the burner surface and different mobility diameters of aggregates. SiO$_2$/TiO$_2$multicomponent particles were generated in a hydrogen/oxygen coflow diffusion flame from two sets of precursors: TTIP(titanium tetraisopropoxide), TEOS(tetraethylorthosilicate). To maintain 1:1 mole ratio of TTIP:TEOS vapor, flow rate of carrier gas $N_2$was fixed at 0.6lpm for TTIP, at 0.1lpm for TEOS. In-situ sampling probe was used to supply particles into DMA(differential mobility analyzer) which was calibrated with using commercial DMA(TSI, model 3071A) and classifying monodisperse multicomponent particles. Classified monodisperse particles were collected with electrophoretic collector. The distributions of composition from particles to particle were determined using EDS(energy dispersive spectrometry) coupled with TEM(transmission electron microscope). The chemical(atomic) compositions of classified monodisperse particle were obtained for different heights; z=40mm, 60mm, 80mm. The results suggested that the chemical(atomic) composition of SiO$_2$decreased with the height from burner surface and the composition of SiO$_2$and TiO$_2$approached to the value of 1 to 1 fat downstream. It is also found that the composition of SiO$_2$decreases as the mobility diameter of aggregate increases.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2000년도 춘계학술대회논문집B
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• pp.441-446
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• 2000

Chemical compositions of monodisperse $SiO_2/TiO_2$ multicomponent aggregates were measured for different heights from the burner surface and different mobility diameters of aggregates. $SiO_2/TiO_2$ multicomponent particles were generated in a hydrogen/oxygen coflow diffusion flame from two sets of precursors: TTIP (titanium tetraisopropoxide), TEOS(tetraethylorthosilicate). To maintain 1:1 mole ratio of TTIP:TEOS vapor theoretically, flow rate of carrier gas $N_2$ was fixed at 0.61pm for TTIP, at 0.11pm for TEOS. In situ sampling probe was used to supply particles into differential mobility analyzer(DMA) which was calibrated with using commercial DMA(TSI 3071A) and classifying monodisperse multicomponent particles. Classified particles were collected with electrophoretic collector. The distributions of composition from particle to particle were determined using EDS (energy dispersive spectrometry) coupled with TEM (transmission electron microscope). The chemical (atomic) compositions of classified monodisperse particle were obtained for different heights; z=40mm, 60mm, 80mm. The results suggested that the atomic composition of $SiO_2$ decreased with the height from burner surface and the composition of $SiO_2$ and $TiO_2$ approached to the value of 1 to 1 in far downstream. It is also found that the composition of $SiO_2$ decreases as the mobility diameter of aggregate increases.