• 제목/요약/키워드: Surface electronic structure

검색결과 924건 처리시간 0.04초

무선 화학센서용으로 다결정 AlN 위에 성장된 나노결정질 ZnO 막의 특성 (Characteristics of nanocrystalline ZnO films grown on polyctystalline AlN for wireless chemical sensors)

  • 레티송;정귀상
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2009년도 추계학술대회 논문집
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    • pp.252-252
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    • 2009
  • In this work, the nanocrystalline ZnO/polycrystalline (poly) aluminum nitride (AlN)/Si structure was fabricated for humidity sensor applications based on surface acoustic wave (SAW). In this structure, the ZnO film was used as sensing material layer. These ZnO and AlN(0002) were deposited by so-gel process and a pulse reactive magnetron sputtering, respectively. These experimental results showed that the obtained SAW velocity on AlN film was about 5128 m/s at $h/\lambda$=0.0125 (h and $\lambda$ is thickness and wavelength, respectively). For ZnO sensing layers coated on AlN, films have hexagonal wurtzite structure and nanometer particle size. The crystalline size of ZnO films annealed at 400, 500, and 600 $^{\circ}C$ is 10.2, 29.1, and 38 nm, respectively. Surface of the film exhibits spongy which can adsorb steam in the air. The best quality of the ZnO film was obtained with annealing temperature at 500 $^{\circ}Cis$. The change in frequency response (127.9~127.85 MHz) of the SAW humidity sensor based on ZnO/AlN structure was measured along the change in humidity (41~69%). The structural properties of thin films wereinvestigated by XRD and SEM.

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셀 구조 변화에 따른 FFL(Flat Fluorescent Lamp)의 방전특성 (Discharge characteristics of FFL as the variation of cell structure)

  • 윤성현;박철현;조민정;임민수;권순석;임기조
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2000년도 하계학술대회 논문집
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    • pp.600-603
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    • 2000
  • Recently, Display devices have become important in the information-oriented society and flat display devices are greatly demanded. Liquid crystal display(LCD) represents one of the most promising devices for large size desk-top monitors, notebook PC and car navigation system. However LCD cannot give forth light itself and must have backlight system. The most popular backlighting system is composed of a lighting-guide plate and CCFL as a lighting source. The number of CCFL must increase up if the area of display is increased. So a new backlighting source with high luminance is needed for large LCDs. In this paper, we proposed a surface discharge FFL with the new electrode structure like the needle shaped electrode as the variation of cell structure to high luminance and low power consumption. In comparison with different electrode structure it has low discharge voltage and current and good optical characteristics. So it has better discharge characteristics than different surface discharge FFL and can be fungible for a backlight as a lighting source in LCDs.

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새로운 정공주입층을 이용한 OLEDs의 특성에 관한 연구 (A Study on the Characteristics of OLEDS Using a New Hole Injection Layer)

  • 심혜연;정지훈;김준호;김영관
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2004년도 하계학술대회 논문집 Vol.5 No.2
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    • pp.1046-1049
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    • 2004
  • The improvement in OLEDS performance is correlated with the surface chemical composition, hole injection and electron injection. In this study, a new hole injection material, HIL202(NPB derivatives), was synthesized and the devices with the structure of ITO/HIL202/NPB/$Alq_3$/Liq/Al were fabricated. The devices with a new hole injection material showed the improved current density, luminance and life time then the NPB or conventional hole injection material based OLEDs, due to the improved adhesion morphology between ITO surface and hole injection material.

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Electrical Properties of MIM and MIS Structure using Carbon Nitride Films

  • Lee, Hyo-Ung;Lee, Sung-Pil
    • Transactions on Electrical and Electronic Materials
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    • 제7권5호
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    • pp.257-261
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    • 2006
  • Nano-structured carbon nitride $(CN_x)$ films were prepared by reactive RF magnetron sputtering with a DC bias at various deposition conditions, and the physical and electrical properties were investigated. FTIR spectrum indicated an ${alpha}C_3N_4$ peak in the films. The carbon nitride film deposited on Si substrate had a nano-structured surface morphology. The grain size was about 20 nm and the deposition rate was $1.7{\mu}m/hr$. When the $N_2/Ar$ ratio was 3/7, the level of nitrogen incorporation was 34.3 at%. The film had a low dielectric constant. The metal-insulator-semiconductor (MIS) capacitors that the carbon nitride was deposited as insulators, exhibited a typical C-V characteristics.

Structural, Morphological and Electrical Properties of TiO2 Thin Films Deposited by ALD Method

  • Seung-Yeon Oh;Jae-Min Shin;Gyeong-Hun Na;Min-Seok Kwon;Sang-Jeen Hong;Bumsuk Jung
    • 반도체디스플레이기술학회지
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    • 제22권2호
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    • pp.87-95
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    • 2023
  • TiO2 thin films were grown using the Atomic Layer Deposition (ALD) and their structural and electrical properties were investigated. The crystal structure, dielectric constant, and surface roughness of the TiO2 thin films grown by the ALD deposition method were studied. The grown TiO2 thin films showed an anatase crystal structure, and their properties varied with temperature. In particular, the properties of the TiO2 thin films were confirmed by changing the process temperature. The electrical properties of Metal-Insulator-Silicon (MIS) capacitor structures were analyzed using a probe station. The performance improvement of capacitors using TiO2 as a dielectric was confirmed by measuring capacitance through Capacitance-Voltage (C-V) curves.

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탄소나노튜브 표면의 STM 이미지를 통한 전기적 특성 연구 (A Theoretical Study on STM image of Carbon Nanotube)

  • 문원하;황호정
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2002년도 하계학술대회 논문집
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    • pp.314-317
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    • 2002
  • Since the early work of Tersoff and Hamann on the theory of the scanning tunneling microscope (STM), many theoretical approaches have been developed in order to gain further physical insight into the real space image that this technique provides. In this Paper, the STM image of Carbon nanotubes (CNT's) was calculated through the theoretical study. The optimized structure of CNT's was simulated using Brenner's hydrocarbon potential. The structure of simulation is (5. 5) armchair CNT and (10. 0) zigzag CNT. Also we have used that the extended Huckel tight binding (EHTB) theory already provides a fairly good qualitative description of the main processes that control the final contrast in the STM image. we found that the shape of the calculated images is hardly dependent on the exact electronic charge distribution at the surface. The STM images are not too sensitive to the precise electronic structure but, rather, they reflect its qualitative features. As a result of the simulation, The STM images of CNT's and the electronic density distribution were investigated. It found that the EHTB theory is appropriate for STM image calculation and that the STM images are in agreement with the result of Experiment.

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