• 제목/요약/키워드: Photoelectronics

검색결과 23건 처리시간 0.026초

Nitrogen source로 ammonia를 사용해 GSMBE로 성장된 GaN 박막 특성 (Growth of GaN on sapphire substrate by GSMBE(gas source molecular beam epitaxy) using ammonia as nitrogen source)

  • 조해종;한교용;서영석
    • 대한전자공학회:학술대회논문집
    • /
    • 대한전자공학회 2004년도 하계종합학술대회 논문집(2)
    • /
    • pp.501-504
    • /
    • 2004
  • High quality GaN layer was obtained on 0001 sapphire substrate using ammonia($NH_3$) as a nitrogen source by gas source molecular beam epitaxy. As a result, RHEED is used to investigate the relaxation processes which take place during the growth of GaN. In-situ RHEED(reflection high electron energy diffraction) appeared streaky-like pattern. The full Width at half maximum of the x-ray diffraction(FWHM) rocking curve measured from plane of GaN has exhibited as narrow as 8arcmin and surface roughness was 7.83nm. Photoluminescence measurement of GaN was investigated at room temperature, where the intensity of the band edge emission is much stronger than that of deep level emission. The GaN epitaxy layer according to various growth condition was investigated.

  • PDF

나노구조 단분자막의 전기적 특성 (Electrical Characteristics of Nano-Structural Monolayer)

  • 최용성;조장훈;송진원;이경섭
    • 한국전기전자재료학회:학술대회논문집
    • /
    • 한국전기전자재료학회 2006년도 추계학술대회 논문집 Vol.19
    • /
    • pp.166-167
    • /
    • 2006
  • Dendrimers represent a new class of synthetic macromolecules characterized by a regularly branched treelike structure. Multiple branching yields a large number of chain ends that distinguish dendrimers from conventional star-like polymers and microgels. The azobenzene dendrimer is one of the dendrimeric macromolecules that include the azo-group exhibiting a photochromic character. Due to the presence of the charge transfer element of the azo-group and its rod-shaped structure, these compounds are expected to have potential interest in electronics and photoelectronics, especially in nonlinear optics. In the present paper, we give pressure stimulation to organic thin films and detect the induced displacement current. Functional photoisometrization organic molecular the photo-stimulus to organic monomolecular L-films and LB films of dendrimer and 8A5H were performed. The 8A5H organic monolayer in case of pressure stimulus occurred that positive course but in case of the photo-stimulus compared positive and negative. It is assumed that generation forms of displacement current were measured when photo-stimulus for Impression.

  • PDF

Molecular Wire World Having Metal Complexes

  • Choi, Chang-Shik
    • Rapid Communication in Photoscience
    • /
    • 제3권3호
    • /
    • pp.42-47
    • /
    • 2014
  • Development of molecular and supramolecular systems showing efficient photoinduced energy or electron transfer are of current research interest due to their applications in various chemical and biological processes. Various polypyridine metal complexes including Ru(II), Ru(III), Os(II), Pt(II), Fe(II), Re(I), Ir(III) and so on as a metal center introduce for expanding some more understanding of molecular-scale photoelectronics. Their complexes are concisely classified by the types of relay ligands as follows; (a) metal-direct ligand-metal system; dinuclear or trinuclear systems, (b) metal-nonconjugated ligand-metal system and metal-nonconjugated ligand system having flexible/rigid ligand, (c) metal-conjugated ligand-metal system, and (d) conjugated ligand-metal-conjugated ligand system and metal-self assembly ligand-metal system. It is pointed out that the role played by the relay ligands is important in constructing the metal complexes.

탄소섬유 물리적 특성 향상을 위한 스퍼터링 탄소박막의 특성에 대한 연구 (Characteristics of Sputtering Carbon Films for the Improvement of Physical Properties in Carbon Fiber)

  • 박철민;박용섭;김재문
    • 한국전기전자재료학회논문지
    • /
    • 제28권11호
    • /
    • pp.694-697
    • /
    • 2015
  • We investigated the characterizations of carbon films fabricated by dual magnetron sputtering under various RF powers for the improvement of physical properties in carbon fiber (CF). All sputtered carbon films exhibited amorphous structure, regardless of RF powers, resulting in uniform and smooth surfaces. The hardness and elastic modulus are increased with the increase of RF power, and the adhesion and friction properties of carbon films were improved with the increase of RF power. In the results, The increase of RF power in the sputtering method improved tribological properties of the carbon films, and these attributes can be expected to improve the physical properties of the carbon fiber reinforcement plastics.

마그네트론 스퍼터링법으로 증착시킨 TiC 박막의 물리적, 전기적 특성에서 RF 파워의 영향 (Effects of RF Power on Physical and Electrical Characteristics of TiC Thin Films Deposited by Magnetron Sputtering)

  • 김남훈;박용섭
    • 한국전기전자재료학회논문지
    • /
    • 제27권7호
    • /
    • pp.458-461
    • /
    • 2014
  • TiC thin films were deposited on Si wafer by unbalanced magnetron sputtering (UBMS) system with two targets of graphite and titanium. During the TiC sputtering, the RF power was varied from 100 W to 175 W and the physical and electrical properties of TiC films were investigated. The hardness and rms surface roughness of TiC films were improved with increasing RF power and the maximum hardness about 24 GPa and the minimum rms surface roughness about 1.2 nm were obtained. The resistivity of TiC films was decreased with increasing RF power. Consequently, the physical and electrical properties of TiC film wewe improved with increasing RF power.

An Efficient Architecture Design of Low Complexity in Quantization of H.264/AVC

  • Lama, Ramesh Kumar;Yun, Jung-Hyun;Kwon, Goo-Rak
    • 한국멀티미디어학회논문지
    • /
    • 제14권10호
    • /
    • pp.1238-1242
    • /
    • 2011
  • An efficient architecture for the reduction of complexity in forward quantization of H.264/AVC is presented in this paper. Since the multiplication operation in forward quantization plays crucial role in complexity of algorithm. More efficient quantization architecture with simplified high speed multiplier is proposed. It uses the modification of the quantization operation and the high speed multiplier is applied for simplification of quantization process.

식물성장용 사각배광 LED 조명 개발 및 평가 (Development and Evaluation of LED Lamp with Rectangular Light Distribution for Growth of Plant)

  • 윤중현
    • 한국전기전자재료학회논문지
    • /
    • 제27권2호
    • /
    • pp.126-131
    • /
    • 2014
  • In this paper, plant crops used in the region to grow crops for the LED lighting area of a rectangle to fit the light distribution to maximize the efficiency of a rectangular distribution was made of LED lights. After the fabrication of LED lamps, light distribution, and in the area of $1.2m{\times}3m$ was the analysis of Illuminance chart. As a result of examining the performance light distribution for total Emin/Eav is 56%, and the target area of the light distribution compared to normal lamps Emin/Eav is improved by about 17%. In addition, plants grown in the area to minimize the outgoing light distribution can be focused on the cultivation area, according to the distance of the plants and be able to have the best luminous efficacy is judged.

DLPC 인지질 단분자막의 변위전류 특성 (Displacement Current Characteristics of DLPC Lipid Monolayer)

  • 최용성;송진원;이경섭
    • 대한전기학회:학술대회논문집
    • /
    • 대한전기학회 2006년도 추계학술대회 논문집 전기물성,응용부문
    • /
    • pp.10-11
    • /
    • 2006
  • The azobenzene dendrimer is one of the dendrimeric macromolecules that include the azo-group exhibiting a photochromic character. Due to the presence of the charge transfer element of the azo-group and its rod-shaped structure, these compounds are expected to have potential interest in electronics and photoelectronics, especially in nonlinear optics. In the present paper, we give pressure stimulation to organic thin films and detect the induced displacement current. Functional photoisometrization organic molecular the photo-stimulus to organic monomolecular L films and LB films of dendrimer and SASH were performed. The SASH organic monolayer in case of pressure stimulus occurred that positive course but in case of the photo-stimulus compared positive and negative. It is assumed that generation forms of displacement current were measured when photo-stimulus for impression.

  • PDF

Reduction of Heat Generation from Junction Box in 3 kW Photovoltaic Power Generation System

  • Yun, Jung-Hyun;Sun, Ki-Ju;Cheon, Min-Woo
    • Transactions on Electrical and Electronic Materials
    • /
    • 제17권1호
    • /
    • pp.21-24
    • /
    • 2016
  • A junction box used in a 3 kW photovoltaic power generation system plays a role in collecting and supplying the direct current voltage produced by photovoltaic modules to an inverter. It is also used for facilitating maintenance checks and protecting the module and inverter by keeping the voltage constant. As for the junction box, using it in a parallel connection creates a difference between the setup modules. In order to compensate, an inverse voltage diode is used. But the high-power created through the solar generator can be delivered to the inverter through the inverter regularly. Therefore, a component can break down due to excess heat. And consequently short circuits and electric leakage occurs. In this study, using a junction box that enabled the bypass of high electric power, it was possible to reduce heat generation by approximately 35℃ when compared to a standard junction box.

기판 온도 변화에 따라 증착되어진 ZnO 박막의 특성과 유기 태양전지의 버퍼층으로의 응용 (Characteristics of ZnO Thin Films Deposited with the Variation of Substrate Temperature and the Application As Buffer Layer in Organic Solar Cell)

  • 박용섭
    • 한국전기전자재료학회논문지
    • /
    • 제28권10호
    • /
    • pp.648-651
    • /
    • 2015
  • The characterizations of zinc oxide (ZnO) buffer layers grown by unbalanced magnetron (UBM) sputtering under various substrate temperatures for inverted organic solar cells (IOSCs) were investigated. UBM sputter grown ZnO films exhibited higher crystallinity with increasing the substrate temperature, resulting in uniform and large grain size. Also, the electrical properties of ZnO films are improved with increasing substrate temperature. In the results, the performance of IOSCs critically depended on the substrate temperature during the film growth because the crystalllinity of the ZnO film affect the carrier mobility of the ZnO film.