• 제목/요약/키워드: semiconductor quantum well

검색결과 101건 처리시간 0.026초

Molecular Dynamics and Quantum Chemical Molecular Dynamics Simulations for the Design of MgO Protecting Layer in Plasma Display Panel

  • Kubo, Momoji;Serizawa, Kazumi;Kikuchi, Hiromi;Suzuki, Ai;Koyama, Michihisa;Tsuboi, Hideyuki;Hatakeyama, Nozomu;Endou, Akira;Takaba, Hiromitsu;Kajiyama, Hiroshi;Shinoda, Tsutae;Miyamoto, Akira
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2008년도 International Meeting on Information Display
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    • pp.1049-1052
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    • 2008
  • We developed novel molecular dynamics and quantum chemical molecular dynamics simulators for the design of MgO protecting layer in plasma display panel. These simulators were applied to the investigations on the destruction processes of the MgO protecting layer as well as the evaluation of its second electron emission ability. From the simulation results, we successfully proposed new guidelines for MgO protecting layer with high durability and high second electron emission ability.

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Electron Microscope Analyses of Self-aligned HgTe Nanocrystallites Induced by Controlled Precipitation Technique

  • Lee, Man-Jong
    • Transactions on Electrical and Electronic Materials
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    • 제3권3호
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    • pp.8-13
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    • 2002
  • Controlled precipitation of quasi-binary semiconductor system is newly proposed as an effective and reliable technique for the formation of well-defined and crystallographically aligned semiconductor nanostructures. Using HgTe-PbTe quasi-binary semiconductor system, self-aligned HgTe nanocrystallites distributed three dimensionally within PbTe matrix were successfully formed by the simple three step heat treatment process routinely found in age hardening process of metallic alloys. Examination of the resulting nano precipitates using conventional transmission electron microscopy (CTEM) and high resolution TEM (HRTEM) reveals that the coherent HgTe precipitates form as thin discs along the (100) habit planes making a crystallographic relation of {100}$\_$HgTe///{100}$\_$PbTe/ and [100]$\_$HgTe///[100]$\_$PbTe/. It is also found that the precipitate undergoes a gradual thickening and a faceting under isothermal aging up to 500 hours without any noticeable coarsening. These results, combined with the extreme dimension of the precipitates (4-5 nm in length and sub-nanometer in thickness) and the simplicity of the formation process, leads to the conclusion that controlled precipitation is an effective method for preparing desirable quantum-dot nanostructures.

Color-stabilized organic light-emitting devices by using N, N'-bis-(1- naphthyl)-N, N'-diphenyl-1,1-biphenyl-4,4'-diamine/5,6,11,12 - tetraphenylnaphthacene multiple quantum well structures

  • Yoon, Y.B.;Kim, T.W.;Yang, H.W.;Lee, H.G.;Kim, J.H.;Kim, Y.G.
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2005년도 International Meeting on Information Displayvol.II
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    • pp.1378-1380
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    • 2005
  • The efficiency and the optical properties of the yellow organic light-emitting devices (OLEDs) were significantly affected by the existence of the multiple quantum well (MQW) structures consisting of N, N'- bis-(1-naphthyl)-N, N'-diphenyl-1,1-biphenyl-4,4'- diamine(NPB)/5,6,11,12 - tetraphenylnaphthacene (rubrene). The maximum efficiency and the luminance of OLEDs with 3-periods of the NPB/rubrene MQWs at 41.6 $mA/cm^2$ were 3.66 cd/A and 1524 $cd/m^2$, respectively, and their Commission Internationale de l'Eclairage chromaticity coordinates were (0.34, 0.55), which indicates a yellow color. These results indicate that the efficiencies of the OLEDs by using MQW emitting layers can be improved.

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양자 우물 소자 모델링에 있어서 다중 에너지 부준위 Boltzmann 방정식의 Self-consistent한 해법의 개발 (Self-consistent Solution Method of Multi-Subband BTE in Quantum Well Device Modeling)

  • 이은주
    • 대한전자공학회논문지SD
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    • 제39권2호
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    • pp.27-38
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    • 2002
  • 양자 우물 반도체 소자 모델링에 있어서 양자 우물의 다중 에너지 부준위 각각에 대한 Boltzmann 방정식의 해를 직접적으로 구하는 self-consistent한 방법을 개발하였다 양자 우물의 특성을 고려하여 Schrodinger 방정식과 Poisson 방정식 및 Boltzmann 방정식으로 구성된 양자 우물 소자 모델을 설정하였으며 이들의 직접적인 해를 유한 차분법과 Gummel-type iteration scheme에 의해 구하였다. Si MOSFET의 inversion 영역에 형성되는 양자 우물에 적용하여 그 시뮬레이션 결과로부터 본 방법의 타당성 및 효율성을 보여 주었다.

Single Mode Lasing in InGaAsP/InP Semiconductor Coupled Square Ring Cavities

  • Hyun, Kyung-Sook;Lee, Taekyu;Moon, Hee-Jong
    • Journal of the Optical Society of Korea
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    • 제16권2호
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    • pp.157-161
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    • 2012
  • This work reports the stability of the resonant characteristics in multimode interferometer coupled square ring semiconductor cavities. Based on the analysis of single square ring cavities, the single mode operations in the multimode interferometer coupled ring cavities are analyzed and the devices are demonstrated on the semiconductor multiple quantum well epitaxial structure. By varying the lasing conditions such as substrate temperature and input pump power, single resonant mode operations are also observed.

비등방성 반도체 양자우물에서의 자유전자 흡수에 의한 광자의 흡수계수의 모델링 (Modeling of free carrier absorption coefficients in anisotropic semiconductor quantum well structures)

  • 김경염
    • 한국광학회지
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    • 제10권1호
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    • pp.80-86
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    • 1999
  • 비등상성 반도체 양자우물에서의 자유전자 흡수에 의한 광자의 흡수계수를 모델링하였다. Intravalley scattering과 interalley scattering에 의한 자유전자 흡수가 모두 고려되었고 양자우물내의 각각의 부밴드가 광자의 흡수에 기여하는 정도도 따로 계산되었다. 또한 이 모델의 타당성을 검증하기 위해, Si에 $\delta$-도핑을 이용하여 형성한 얀자우물에 대하여 시물레이션을 수행하고 문헌의 실현결과와 비교하여 그 적절성을 보였다.

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Ultradense 2-to-4 decoder in quantum-dot cellular automata technology based on MV32 gate

  • Abbasizadeh, Akram;Mosleh, Mohammad
    • ETRI Journal
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    • 제42권6호
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    • pp.912-921
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    • 2020
  • Quantum-dot cellular automata (QCA) is an alternative complementary metal-oxide-semiconductor (CMOS) technology that is used to implement high-speed logical circuits at the atomic or molecular scale. In this study, an optimal 2-to-4 decoder in QCA is presented. The proposed QCA decoder is designed using a new formulation based on the MV32 gate. Notably, the MV32 gate has three inputs and two outputs, which is equivalent two 3-input majority gates, and operates based on cellular interactions. A multilayer design is suggested for the proposed decoder. Subsequently, a new and efficient 3-to-8 QCA decoder architecture is presented using the proposed 2-to-4 QCA decoder. The simulation results of the QCADesigner 2.0.3 software show that the proposed decoders perform well. Comparisons show that the proposed 2-to-4 QCA decoder is superior to the previously proposed ones in terms of cell count, occupied area, and delay.

Synthesis of Quantum Dot-Tagged Submicrometer Polystyrene Particles by Miniemulsion Polymerization

  • Joumaa, Nancy;Lansalot, M.;Theretz, A.;Elaissari, A.;Sukhanova, A.;Artemyev, M.;Nabiev, I.;Cohen, J.H.M.
    • 한국고분자학회:학술대회논문집
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    • 한국고분자학회 2006년도 IUPAC International Symposium on Advanced Polymers for Emerging Technologies
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    • pp.330-330
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    • 2006
  • The elaboration of fluorescent submicronic polymer particles exhibiting narrow particle size distribution as well as good photostability is of particular interest in various biomedical applications. In the frame of this work, labeled polystyrene latexes have been synthesized by miniemulsion polymerization using luminescent semiconductor nanoparticles (quantum dots, QD). The influence of incorporation of QDs on the polymerization kinetics as well as on the optical properties of the obtained latexes will be discussed.

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Structural Characteristics on InAs Quantum Dots multi-stacked on GaAs(100) Substrates

  • Roh, Cheong-Hyun;Park, Young-Ju;Kim, Eun-Kyu;Shim, Kwang-Bo
    • 마이크로전자및패키징학회지
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    • 제7권1호
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    • pp.25-28
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    • 2000
  • 분자선에피택시법에 의하여 GaAs(100)기판 위에 InAs 자발형성양자점을 성장하였다. InAs 양자점은 1, 3, 6, 10, 15 및 20층 등으로 다양하게 적층되어졌고, GaAs 층과 InAs 양자점 층은 각각 20 MLs와 2 MLs의 두께를 갖도록 하였다. 이 양자점의 나노구조적 특성은 PL과 STEM을 사용하여 분석하였다. 가장 높은 PL 강도는 6층의 적층구조를 갖는 시편에서 나타났고 PL 피크의 에너지가 적층회수가 증가함에 따라 분리됨을 알 수 있었다. STEM분석결과, 6충의 적층구조에서는 결함이 거의 없이 수직으로 형성된 구조를 보여준 반면에 10층 이상의 적층구조를 가질 때 그 성장 방향에 따라 volcano형상을 갖는 결함이 수직하게 성장되어졌다.

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