• 제목/요약/키워드: Quantum-well

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Modeling of Degenerate Quantum Well Devices Including Pauli Exclusion Principle

  • 이은주
    • 대한전자공학회논문지SD
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    • 제39권2호
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    • pp.14-26
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    • 2002
  • Pauli 배타 원리를 적용한 축퇴 상태의 양자 우물 소자 모델링을 제안하였다. 양자 우물에서의 다중 에너지 부준위 각각에 대한 Boltzmann 방정식의 collision 항들을 Pauli 배타 원리를 적용하여 전개하고 이들을 Schrodinger 방정식과 Poisson 방정식과 결합하여 비선형적인 시스템의 모델을 설정하였다. 시스템의 해를 직접적으로 구하기 위하여 유한 차분법과 Newton-Raphson method를 적용하여 양자 우물의 다중 에너지 부준위 각각에 대한 캐리어 분포 함수를 구하였다. Si MOSFET의 inversion 영역에 본 모델을 적용하여 전자 밀도의 증가에 따라 양자 우물의 에너지 분포 함수가 Boltzmann 분포 함수의 형태로부터 Fermi-Dirac 분포 함수의 형태로 변화함을 제시하고, 소자 크기가 감소할수록 소자 모델링에 있어서의 Pauli 배타 원리의 중요성과 함께 본 모델의 정당함과 그 해석 방법의 효율성을 보여주었다.

양자우물 레이저의 이득 곡선의 온도 의존성 (Temperature Dependence of the Gain Spectrum of a Quantum Well Laser)

  • 김동철;유건호;박종대;김태환
    • 한국광학회지
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    • 제6권4호
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    • pp.302-309
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    • 1995
  • 상온에서 $1.55{\mu}m$ 를 발진하는 격자 정합된 InGaAs/InGaAsP 양자우물 레이저를 설계하여 주입 운반자 밀도와 온도의 함수로 이득 곡선을 계산하였다. 밴드 구조와 운동량 행력 요소의 계산에는 블록대각화된 8*8 이차 k.p 해밀토니안에 근거한 변환행렬법을 사용하였다. 이 격자정합된 양자우물은 TE 모우드로 발진하였다. 온도가 증가함에 따라 발진파장이 길어졌고, 투명 운반자 밀도는 증가하였으며 미분이득은 감소하였다. 이득 곡선의 온도의존도는 밴드 구조의 온도의존성과 페르미 함수의 온도의존성에 기인하는데 이중 후자의 효과가 주도적인 것이었다.

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MOCVD법에 의한 (Ga, Al) As/GaAs 변형된 영지우물 레이저 다이오드의 제작 (The Fabrication of (Ga, Al) As/GaAs Modified Multi-Quantum Well Laser Diode by MOCVD)

  • 김정진;강명구;김용;엄경숙;민석기;오환술
    • 전자공학회논문지A
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    • 제29A권9호
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    • pp.36-45
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    • 1992
  • The Modified Multi-Quantum Well(MMQWAl) structures have been grown by Mental-Organic chemical Vapor Deposition(MOCVD) method and stripe type MMQW laser diodes have been investigated. In the case of GaAs/AlGaAs superlattice and quantum well growth by MOCVD, the periodicity, interface abruptess, Al compositional uniformity and layer thickness have been confirmed though the shallow angle lapping technique, double crystal x-ray diffractometry (DCXD) and photoluminescence (PL) measurement. stripe-type MMQW laser diodes have been fabricated using the process technology of photolithography, chemical etching, ohmic contact, back side removing and cleaving. As the result of the electrical and opticalmeasurement of these laser diodes, we have achieved the series resistance of $1[\Omega}~2{\Omega}$ by current-voltage measurements, the threshold current of 200-300mA by currnt-light measurements and the lasing wavelength of 8000-8400$\AA$ by lasing spectrum measurements.

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SCH 양자우물 레이저 다이오드의 수송기구와 변조응답 특성에 관한 연구 (A Study on the Transport Mechanism of a SCH Quantum-Well Laser Diode and on the Modulation Characteristics)

  • 김종기;정재용;서정하
    • 대한전자공학회논문지TE
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    • 제37권1호
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    • pp.27-34
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    • 2000
  • 본 논문에서는 SCH 양자우물 구조를 가진 레이저 다이오드에서의 캐리어 수송기구와 변조응답 특성에 대해 고찰하였다. 캐리어 수송구조 고찰을 위해 캐리어 밀도분포및 다이오드전류를 계산하였다. 또한 우물내에서의 캐리어 재결합율을 SCH길이의 함수로 도출하였다. 변조응답 특성에서는 캐리어와 광자에 대한 3쌍의 비율 방정식을 도출, 해석하여 SCH 길이에 따른 변조 대역폭과 완화 진동 주파수, 감쇄 비율과 K-factor의 특성에 대하여 고찰하였다.

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비대칭 다중 양자우물 레이저 다이오드에서 모드이득의 이론 및 실험적 분석 (Theoretical and experimental analysis of modal gain in asymmetric multiple quantum well laser diodes)

  • 권오기;김강호;김현수;김종회;오광룡
    • 한국광학회지
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    • 제14권3호
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    • pp.279-285
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    • 2003
  • InGaAsP/InP 비대치 다중 양자우물 구조에서 모드 이득의 이론 및 실험적 해석을 통해 광대역 이득특성을 확인하였고, 여러가지 선폭증가 함수를 적용하여 비대칭 선폭증가 함수가 가장 실험치에 근접한 모델임을 확인하였다. 광대역 이득 대역폭을 얻기 위한 활성층 구조를 설계하여 RWG형 FP-LD를 제작하였고, 공진기 길이가 400 $\mu\textrm{m}$에서 발진개시 전류는 36 ㎃, 주입전류가 33 ㎃에서 -1 ㏈ 이득폭은 45 nm, -3 ㏈ 폭은 80 nm을 얻을 수 있었다.

Effect of electric field on primary dark pulses in SPADs for advanced radiation detection applications

  • Lim, Kyung Taek;Kim, Hyoungtaek;Kim, Jinhwan;Cho, Gyuseong
    • Nuclear Engineering and Technology
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    • 제53권2호
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    • pp.618-625
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    • 2021
  • In this paper, the single-photon avalanche diodes (SPADs) featuring three different p-well implantation doses (∅p-well) of 5.0 × 1012, 4.0 × 1012, and 3.0 × 1012 atoms/cm2 under the identical device layouts were fabricated and characterized to evaluate the effects of field enhanced mechanisms on primary dark pulses due to the maximum electric field. From the I-V curves, the breakdown voltages were found as 23.2 V, 40.5 V, and 63.1 V with decreasing ∅p-well, respectively. By measuring DCRs as a function of temperature, we found a reduction of approximately 8% in the maximum electric field lead to a nearly 72% decrease in the DCR at Vex = 5 V and T = 25 ℃. Also, the activation energy increased from 0.43 eV to 0.50 eV, as decreasing the maximum electric field. Finally, we discuss the importance of electric field engineering in reducing the field-enhanced mechanisms contributing to the DCR in SPADs and the benefits on the SPADs related to different types of radiation detection applications.

수온환경변화에 따른 생물분포와 어업피해결정을 위한 임계환경변화량이론의 재조명 (Biological Distribution by Water Temperature and Refocus on the Theory of Critical Environmental Variation Quantum)

  • 강용주;김기수
    • 수산경영론집
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    • 제45권1호
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    • pp.1-16
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    • 2014
  • The study attempts to show that the theory of critical environmental variation quantum(CEVQ) has a sound logical basis and empirical support. It is well known that the theory of critical environmental variation quantum is derived from the theory of biological probability distibution function and the central limit theorem(CLT) in statistics. The study uses the case study of fisheries damages compensation caused br the public marine construction undertaken in the area do Anjeong Bay in the city of Tongyeong for empirical test of theory of CEVQ. The results shows that the CEVQ theory perfoms a good job in measuring quantatively fjsheries damages caused by outflow of cold water due to the operation of LNG company since 2002. Therefore the study proves that the CEVQ theory is a good theory having internal consistency and empirical applicability.

The magnetic dependence of 2-dimension quantum optical transition in electron-deformation potential phonon interaction systems in Ge

  • Choi, Hyenil;Cho, Hyunchul;Lee, Suho
    • 전기전자학회논문지
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    • 제22권2호
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    • pp.446-454
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    • 2018
  • In this work, we summarize the calculation processes of obtaining a scattering factor using with the equilibrium average projection scheme (EAPS), with moderately weak coupling (MWC) interaction, and obtain the line-shape formula of an electron-deformation phonon interacting system interested in the confinement of electrons by squarwell confinement potentials in quantum two dimensional system.. Through the numerical analysis, we analysis the magnetic dependence of absorption power, P(B) in several temperature and frequency difference dependence of absorption power $P({\Delta}{\omega})$, in several external field, where ${\Delta}{\omega}={\omega}-{\omega}_0$ and ${\omega}({\omega}_0)$ is the angular frequency (the cyclotron resonance frequency). The result of equilibrium average projection scheme (EAPS) in SER-MWC explains the properties of quantum transition quite well.

Quantum Nanostructure of InGaAs on Submicron Gratings by Constant Growth Technique

  • Son, Chang-Sik
    • 한국전기전자재료학회논문지
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    • 제14권12호
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    • pp.1027-1031
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    • 2001
  • A new constant growth technique to conserve an initial grating height of V-groove AlGaAs/InGaAs quantum nanostructures above 1.0 $\mu\textrm{m}$ thickness has been successfully embodied on submicron gratings using low pressure metalorganic chemical vapor deposition. A GaAs buffer prior to an AlGaAs barrier layer on submicron gratings plays an important role in overcoming mass transport effects and improving the uniformity of gratings. Transmission electron microscopy (TEM) image shows that high-density V-groove InGaAs quantum wires (QWRs) are well confined at the bottom of gratings. The photoluminescence (PL) peak of the InGaAs QWRs is observed in the temperature range from 10 to 280 K with a relatively narrow full width at half maximum less than 40 meV at room temperature PL. The constant growth technique is an important step to realize complex optoelectronic devices such as one-step grown distributed feedback lasers and two-dimensional photonic crystal.

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Dependence of Optical Matrix Elements on the Boundary Conditions of the Continuum States in Quantum Wells

  • Jang Y. R.;Yoo K. H.;Ram-Mohan L. R.
    • Journal of the Optical Society of Korea
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    • 제9권2호
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    • pp.39-44
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    • 2005
  • Unlike for the bound states, several different boundary conditions are used for the continuum states above the barrier in semiconductor quantum wells. We employed three boundary conditions, infinite potential barrier boundary condition, periodic boundary condition and scattering boundary condition, and calculated the local number of states, wavefunctions and optical matrix elements for the symmetric and asymmetric quantum wells. We discussed how these quantities are related in the three boundary conditions. We argue that the scattering boundary condition has several advantages over the other two cases. These results would be useful in understanding quantum well lasers and detectors involving continuum states.