• 반도체디스플레이기술학회지
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• 제18권4호
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• pp.120-123
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• 2019

The effect of surface plasmon on ZTO thin films was investigated. The phenomenon of depletion occurring in the interface of the ZTO thin film created a potential barrier and the dielectric layer of the depletion formed a non-mass particle called plasmon. ZTO thin film represents n-type semiconductor features, and surface current by plasma has been able to obtain the effect of improving electrical efficiency as a result of high current at positive voltage and low current at negative voltage. It can be seen that the reduction of electric charge due to recombination of electronic hole pairs by heat treatment of compound semiconductors induces higher surface current in semiconductor devices.

• Journal of the Optical Society of Korea
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• 제17권1호
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• pp.10-15
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• 2013

Adsorption behavior of counterions under a Langmuir monolayer was investigated by sum-frequency generation (SFG) spectroscopy. By comparing SFG spectra of arachidic acid (AA) Langmuir monolayer/water interface with and without added salt, it was found that the simple trivalent cation $La^{3+}$ adsorbed on AA monolayer only when the carboxylic headgroups are charged (deprotonated), implying that counterion adsorption is induced by Coulomb interaction. On the other hand, metal hydroxide complex $Fe(OH)_3$ adsorbed even on a charge-neutral AA monolayer, indicating that the adsorption of iron hydroxide is due to chemical interaction such as covalent or hydrogen bonding to the headgroup of the molecules at the monolayer.

• Journal of Industrial and Engineering Chemistry
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• 제67권
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• pp.486-496
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• 2018

Bimetallic Pd@Ni nanostructure exhibited enhanced co-catalytic activity for the selective hydrogenation of benzaldehyde compare to their monometallic counterparts. Impregnation of these mono/bimetallic nanostructures on mesoporous $TiO_2$ leads to several surface modifications. The bimetallic PNT-3 ($Pd_3@Ni_1/mTiO_2$) exhibited large surface area ($212m^2g^{-1}$), and low recombination rate of the charge carriers ($e^--h^+$). The hydrogenation reaction was analyzed under controlled experiments. It was observed that under UV-light irradiations and saturated hydrogen atmosphere the bimetallic PNT-3 photocatalyst display higher rate constant $k=5.31{\times}10^{-1}h^{-1}$ owing to reduction in the barrier height which leads to efficiently transfer of electron at bimetallic/$mTiO_2$ interface.

• Journal of information and communication convergence engineering
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• 제18권4호
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• pp.245-253
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• 2020

The human body and nervous system transmit information through electric charges. After the electric charge transmits information to the brain, we can feel pain, numbness, comfort, and other feelings. Electric therapy is currently used widely in clinical practice because the field of examination is more representative of electrocardiogram, and in the field of treatment is more representative of electrotherapy. In this study, we design a system for neurophysiological therapy and conduct parameter calculation and model selection for the components of the system. The system is based on a discontinuous conduction mode (DCM) boost circuit, and controlled and regulated by a single-chip microcomputer. The system does not only have a low cost but also fully considers the safety of use, convenience of the human-computer interface, adjustment sensitivity, and waveform diversity in the design. In future, it will have strong implications in the field of electrotherapy.

• 반도체디스플레이기술학회지
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• 제21권3호
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• pp.114-118
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• 2022

The stabilized all-solid-state battery structure indicate a fundamental alternative to the development of next-generation energy storage devices. Existing liquid electrolyte structures severely limit battery stability, creating safety concerns due to the growth of Li dendrites during rapid charge/discharge cycles. In this study, a low-dimensional graphene quantum dot layer structure was applied to demonstrate stable operating characteristics based on Li+ ion conductivity and excellent electrochemical performance. Transmission electron microscopy analysis was performed to elucidate the microstructure at the interface. The low-dimensional structure of GQD-based solid electrolytes has provided an important strategy for stable scalable solid-state lithium battery applications at room temperature. This study indicates that the low-dimensional carbon structure of Li-GQDs can be an effective approach for the stabilization of solid-state Li matrix architectures.

• 산업기술연구
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• 제43권1호
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• pp.43-48
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• 2023

Spinel LiNi_0.5Mn_1.5O₄ (LNMO) has been considered as one of most promising cathode material, because of its low-cost and competitive energy density. However, 4.7V vs. Li/Li⁺ of high operating potential facilitates electrolyte degradation on cathode-electrolyte interface during charge-discharge process. In particular, commercial polyvinylidene fluoride (PVDF) is not sutaible for LNMO cathode binder because its weak van der waals force induces thick and non-uniform coverage on the cathode surface. In this review, we study high performance binders for LNMO cathode, which forms uniform coating layer to prevent direct contact between electrolyte and LNMO particle as well as modifying high quality cathode electrolyte interphase, improved cell performace.

• 한국결정성장학회지
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• 제11권5호
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• pp.224-230
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• 2001

초박막 게이트 유전막 및 비휘발성 기억소자의 게이트 유전막으로 연구되고 있는 $NO/N_2O$ 열처리된 재산화 질화산 화막의 특성을 D-SIMS(Dynamic Secondary Ion Mass Spectrometry), ToF-SIMS(Time-of-Flight Secondary Ion Mass Spectrometry), AES(Auger Electron Spectroscopy)으로 조사하였다. 시료는 초기산화막 공정후에 NO 및 $N_2O$ 열처리를 수행하였으며, 다시 재산화공정을 통하여 질화산화막내 질소의 재분포를 형성토록하였다. 재산화에 있어서 습식산화시 공정에 사용된 수소에 의한 영향으로 계면 근처에 축적된 질소가 Si≡N 결합을 쉽게 이탈함에 따라 방출이 촉진되어 건식산화에 비하여 질소의 감소가 더욱 두드러지게 나타났다. 재산화에 따른 질화산화막내 질소의 거동은 외부로의 방출과 기판으로의 확산이 동시에 나타난다. 재산화후 질화산화막내 축적된 질소의 결합종을 분석한 결과, 초기산화막 계면근처의 질소는 SiON의 결합종이 주도적으로 나타나는 반면 재산화 후 새롭게 형성된 $Si-SiO_2$ 계면근처로 확산한 질소는 $Si_2NO$ 결합종이 주로 검출된다. SiON에 의한 질소의 미결합손과 $Si_2$NO에 의한 실리콘의 미겨랍손은 기억특성에 기여하는 결함을 포함하기 때문에 재산화 질화산화막내 존재하는 SiON과 $Si_2$NO 결합종은 모두 전하트랩의 기원과 관련된 결합상태로 예상된다.

• 전자공학회논문지SC
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• 제41권1호
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• pp.25-32
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• 2004

교통 분야에서도 역시 영상을 이용한 시스템의 개발이 주요 이슈가 되고 있다. 이는 영상을 이용한 시스템의 경우 설치비용이 기존 시스템들에 비해 엄청나게 저렴하다는 것과 설치하는 기간 중에도 교통의 흐름을 거의 방해하지 않고 설치가 가능하다는 장점을 가지고 있기 때문이다. 본 연구에서는 임베디드 시스템 환경에서 영상 검지기 시스템의 구현을 제안하였다. 전체 시스템은 호스트 컨트롤러 보드부분과 영상처리 보드 부분으로 나뉜다. 호스트 컨트롤러 보드 부분은 전체 시스템의 제어와 외부와의 인터페이스, 그리고 OSD(On Screen Display) 부분을 담당하게 된다. 영상처리 보드 부분은 알고리즘의 적용, 마우스 신호의 베어를 담당하고 있다 그리고 안정적인 호스트 컨트롤러의 보드의 운영을 위해 uC/OS-II 를 호스트 컨트롤러 보드에 포팅하였다.

• 한국세라믹학회지
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• 제53권4호
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• pp.400-405
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• 2016

Ferric oxide (${\alpha}-Fe_2O_3$, hematite) is an n-type semiconductor; due to its narrow band gap ($E_g=2.1eV$), it is a highly attractive and desirable material for use in solar hydrogenation by water oxidation. However, the actual conversion efficiency achieved with $Fe_2O_3$ is considerably lower than the theoretical values because the considerably short diffusion length (2-4 nm) of holes in $Fe_2O_3$ induces excessive charge recombination and low absorption. This is a significant hurdle that must be overcome in order to obtain high solar-to-hydrogen conversion efficiency. In consideration of this, it is thought that elemental doping, which may make it possible to enhance the charge transfer at the interface, will have a marked effect in terms of improving the photoactivities of ${\alpha}-Fe_2O_3$ photoanodes. Herein, we report on the synthesis by pulsed electrodeposition of ${\alpha}-Fe_2O_3$-based anodes; we also report on the resulting photoelectrochemical (PEC) properties. We attempted Ti-doping to enhance the PEC properties of ${\alpha}-Fe_2O_3$ anodes. It is revealed that the photocurrent density of a bare ${\alpha}-Fe_2O_3$ anode can be dramatically changed by controlling the condition of the electrodeposition and the concentration of $TiCl_3$. Under optimum conditions, a modified ${\alpha}-Fe_2O_3$ anode exhibits a maximum photocurrent density of $0.4mA/cm^2$ at 1.23 V vs. reversible hydrogen electrode (RHE) under 1.5 G simulated sunlight illumination; this photocurrent density value is about 3 times greater than that of unmodified ${\alpha}-Fe_2O_3$ anodes.

• 한국컴퓨터산업학회논문지
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• 제6권2호
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• pp.357-364
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• 2005

최근 들어 우리나라에서는 설치의 간편성과 높은 신뢰도를 가진 전력케이블의 사용이 증가하고 있다. 전력케이블은 출고 전에 IEEE std. 404-1993 시험을 거쳐 안정성을 확인하고 있지만 포설시 발생하는 접속부 내부의 결함으로 인하여 많은 문제가 발생하고 있다. 특히 불순물 혼입 또는 공극 발생시 고장율은 증가하게 된다 부분방전 검출은 포설 후 전력케이블의 상태를 관측할 수 있는 유용한 방법이다. 본 연구에서는 부분방전 특성을 평가하고자 케이블 접속재인 EPR과 케이블 절연체인 XPLE 사이에 인공 결함을 발생시킨 후 데이터 취득 시스템을 이용하여 $\Phi-q-n$ 특성을 검출하였으며, 부분방전의 정량적 해석을 위해 필요한 통계량을 계산하였으며, 신경망 모델을 적용하여 패턴 분석을 수행하여 $88\~96\%$의 구별이 가능하였다.