• 제목/요약/키워드: bandgap

검색결과 643건 처리시간 0.045초

증착 온도가 RF 반응성 마그네트론 스퍼터링법으로 성장된 InN 박막의 특성에 미치는 영향 (Effects of Deposition Temperature on the Properties of InN Thin Films Grown by Radio-frequency Reactive Magnetron Sputtering)

  • 조신호
    • 한국전기전자재료학회논문지
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    • 제22권10호
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    • pp.808-813
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    • 2009
  • Indium nitride thin films were deposited by the radio-frequency reactive magnetron sputtering method. The indium target was sputtered by the mixture flow ratio of $N_2$ to Ar, 9:1. The effects of growth temperature on the structural, optical, and electrical properties of the films were investigated. With increasing the growth temperature, the crystallinity of the films was improved, and the crystalline size was increased. The energy bandgap for the film grown at $25^{\circ}C$ was 3.63 eV, and the bandgap showed an increasing tendency on the growth temperature. The carrier concentration, Hall mobility and electrical resistivity of the films depended significantly on the growth temperature and the maximum Hall mobility of $32.3\;cm^2$/Vsec was observed for the film grown at $400^{\circ}C$.

Rhodomine B dye removal and inhibitory effect on B. subtilis and S. aureus by WOx nanoparticles

  • Ying, Yuet Lee;Pung, Swee Yong;Ong, Ming Thong;Pung, Yuh Fen
    • Journal of Industrial and Engineering Chemistry
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    • 제67권
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    • pp.437-447
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    • 2018
  • Visible-light-driven wide bandgap semiconductor photocatalysts were commonly developed via doping or coupling with another narrow bandgap metal oxide. However, these approaches required extra processing. The aim of study was to evaluate the photocatalytic performance of narrow bandgap $WO_x$ nanoparticles. A mixture of $WO_2$ and $WO_3$ nanoparticles were synthesized using solution precipitation technique. The photodegradation of RhB by these nanoparticles more effective in UV light than in visible light. In antibacterial susceptibility assay, $WO_x$ nanoparticles demonstrated good antibacterial against Gram-positive bacteria. The cell wall of bacterial was the main determinant in antibacterial effect other than $W^{4+}/W^{6+}$ ions and ROS.

PBG를 이용한 광대역 전방급전 전력증폭기의 성능개선에 관한 연구 (Improvement of Broadband Feedforward Amplifier Using Photonic Bandgap)

  • 윤진호;서철헌
    • 한국통신학회논문지
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    • 제26권4B호
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    • pp.406-409
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    • 2001
  • 본 논문에서는 IMT-2000 대역에서 전방급전 전력증폭기의 선형성을 개선하여 효율과 대역폭을 극대화 하기 위해 Photonic Bandgap(PBG), 전치왜곡, 2차고조파 튜닝 방식으 f동시에 주 증폭기에 적용하였다. 2차 하모닉 성분이 2차고조파 튜닝 방식에 의해 우수하게 제거되고, 3차 하모닉 성분이 전치왜곡 방식에 의해 제거되며 출력단위 PBG느 s고아대역 특성으로 4차 하모닉 이상까지 제거하는 우수한 특성을 보여주었다. 총체적으로 기존의 전방급전 전력증폭기보다 IMD가 최고 15dBc, 효율은 4%, 대역폭은 2배이상 확대됨으로 전력효율과 대역폭을 극대화시킬 수 있었다.

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밴드갭 기준 전압을 이용한 CMOS 전압 제어 발진기의 설계 (A Design of CMOS VCO Using Bandgap Voltage Reference)

  • 최진호
    • 대한전기학회논문지:전기물성ㆍ응용부문C
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    • 제52권10호
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    • pp.425-430
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    • 2003
  • A CMOS Voltage-Controlled Oscillator(VCO) for application at temperature stable system is designed. The VCO consists of bandgap voltage reference circuit, comparator, and voltage-to-current converter and the VCO has a temperature stable characteristics. The difference between simulated and calculated values is less than about 5% in output characteristics when the input voltage range is from 1V to 3.25V. The CMOS VCO has error less than about $\pm$0.85% in the temperature range from $-25^{\circ}C$ to $75^{\circ}C$.

A New Curvature-Compensated CMOS Bandgap Reference with Low Power Consumption

  • Gil, JoonHo;Je, Minkyu;Cho, YoungHo;Shin, Hyungcheol
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 2000년도 ITC-CSCC -2
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    • pp.612-614
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    • 2000
  • We propose a new curvature-compensated CMOS bandgap reference circuit that is achieved by varying a current ratio. The proposed circuit is shown to have small temperature coefficient that the output voltage variation is 0.4mV.

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Bandgap Tuning in InGaAs/InGaAsP Laser Structure by Quantum Well Intermixing

  • Nah Jongbum;Kam PatrickLi
    • 한국광학회지
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    • 제16권2호
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    • pp.159-161
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    • 2005
  • We report the selective area bandgap tuning of multiple quantum well structures by an impurity free vacancy induced quantum well intermixing technique. A 3dB waveguide directional coupler was fabricated in the disordered section of an intermixed quantum well sample as a demonstration of photonic device applications.