Many Body Effects and Dynamics of High Density Excitons in Semiconductor Nano-Crystals

半导体纳米晶体中高密度激子的许多体效应和动力学

• 批准号: 12640319
• 负责人: AKAI Ichiro
• 金额: $ 2.37万
• 依托单位: Osaka City University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2000
• 资助国家: 日本
• 起止时间: 2000 至 2001
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-12640319/
• 关键词: Semiconductor Nanostructure; Exciton; High Density Excitation; Many Body Effect; Dynamics of Photo-Excited States; Nonlinear Optical Effects; Luminescent Organic Dyes; Condensed Matter Physics; 物生物理学

(1) Many body effects and dynamics of excitons in AlGaAs/AIAs semiconductor quantum wiresMany body effects and their dynamics of excitonic photoluminescence (PL) in Al_xGa_<1-x>As/AlAs semiconductor quantum wires (QWR's) have been studied. It has been clarified that an accumulation dynamics of the excitons among the QWR's plays an important role on the dynamics of the many body effects. And as a result, a phase space filling effect of the high density excitons gives rise to the blue shift of the PL under high density excitation. On the other hand, an asymmetric diffusion of the excitons along the QWR's was observed. Under high density excitation, an enhancement of the exciton diffusion has been revealed.(2) Many body effects and dynamics of excitons in nano-interfaces of layered semiconductorsTemporal and spatial dynamics of the excitons localized at the nano-interface in BiI_3, have been investigated by a spatially resolved degenerated four wave mixing technique. As a result, It has b … More een clarified that the quantum state of the excitons propagate macroscopically in keeping the quantum coherency. The spatial propagation dynamics of the exciton quantum states can be explained by a Gross-Pitaevskii equation including a weak repulsive interaction among excitons.(3) Many body effects and dynamics of excitons in semiconductor microcrystallites in matricesMicrocrystallites of Cul, HgI_2,PbI_2 and TII embedded in the porus polymers and glasses have been grown. Many body effects and exciton-lattice interactions of the excitons in the microcrystallites have been studied. In Cul and HgI_2, novel crystal structures and novel exciton transitions appear as a result of micro-crystallization. On these exciton system, nonlinear luminescences of the bi-excitons and the inelastic scattering of the excitons were observed. It has been cleared that the mechanism of the many body effects changes by changing the crystal size, temperature and excitation density. On the other hand, on the microcrystallites of TII, HgI_2 and PbI_2, the exciton-lattice interactions are enhanced by the interaction between the microcrystallites and matrices. In the case of TII and HgI_2, the effective energy transfer from the matrices to the maicrocrystallites governs the dynamics of the nonlinear luminescence of the excitons.(4) Dynamics of excitons in functional organic semiconductor nano-moleculesDynamics of the photo-excited states providing the luminescence of the luminous organic dye Alq3 and the hexanuclear 6-Methylpyridinethiolato-Copper (I) have been studied. On the Alq3, we have proposed a new model for the photo-excited state including two-luminescent states and a intermediate state mediating thermal activation. On the other hand, the origin and dynamics of the photo excited states have been revealed. Less

(1)AlGaAs/AlAs半导体量子线中激子的多体效应及其动力学研究了Al_xGa_ As/AlAs半导体量子线中激子光致发光（PL）的多体效应及其动力学<1-x>。它已被澄清的激子之间的QWR的积累动力学起着重要的作用的动力学的多体效应。结果表明，高密度激子的相空间填充效应导致了高密度激发下光致发光的蓝移。另一方面，观察到激子沿着QWR的不对称扩散。在高密度激发下，激子扩散的增强已被揭示。(2)本文用空间分辨简并四波混频技术研究了BiI_3中纳米界面上局域激子的时空动力学。因此，它具有B ...更多信息 阐明了激子的量子态在保持量子相干性的情况下宏观地传播。激子量子态的空间传播动力学可以用包含激子间弱排斥相互作用的Gross-Pitaevskii方程来解释。(3)在多孔聚合物和玻璃中生长了CuI，HgI_2，PbI_2和TII微晶。微晶中激子的许多体效应和激子-晶格相互作用已被研究。在CuI和HgI_2中，由于微晶化，出现了新的晶体结构和新的激子跃迁。在这些激子系统上，观察到了双激子的非线性发光和激子的非弹性散射。通过改变晶体的尺寸、温度和激发密度，可以改变多体效应的机理。另一方面，在TII、HgI_2和PbI_2微晶上，由于微晶与基体的相互作用，激子-晶格相互作用增强。在TII和HgI_2的情况下，从基质到微晶的有效能量转移决定了激子的非线性发光动力学。(4)功能有机半导体纳米分子中激子的动力学研究了发光有机染料Alq 3和六核6-甲基吡啶硫醇合铜（I）的光激发态动力学。在Alq 3上，我们提出了一个新的光激发态模型，包括两个发光态和一个介导热激活的中间态。另一方面，揭示了光激发态的起源和动力学。少

项目成果

Kazuki Bando: "Optical Properties of Al_xGa_<1-x>As/AlAs Quantum Wires under High Density Excitation"Memories of The Institute of Scientific and Industrial Research, Osaka University, Special Issue. 57. 281-282 (2000)

坂东一树：“高密度激发下Al_xGa_<1-x>As/AlAs量子线的光学性质”大阪大学科学工业研究院回忆，特刊。

Yasuyuki Shirasaka: "Spatial Behavior of Exciton-Polariton Masses in a Layered Crystal BiI_3"International Journal of Modern Physics B. 15. 3960-3964 (2001)

Yasuyuki Shirasaka：“层状晶体 BiI_3 中激子-极化子质量的空间行为”国际现代物理学杂志 B. 15. 3960-3964 (2001)

M. Yamamoto, H. Mino, I. Akai, T. Karasawa, V.F. Aguekian: "Space-Resolved Luminescence and Degenerate Four-Wave-Mixing Spectra of Heavily Photo-Created Exciton States in a Layered Crystal GaSe"Journal of Luminescence. 87-89. 275-277 (2000)

M. Yamamoto、H. Mino、I. Akai、T. Karasawa、V.F.

Y. Shirasaka, A. Tanji, I. Akai, T. Karasawa: "Coherent Motion of High-Density Exciton Masses at a Quasi Two-Dimensional Interface in Bil_3"Journal of Luminescence. 94-95. 433-436 (2002)

Y. Shirasaka、A. Tanji、I. Akai、T. Karasawa：“Bil_3 中准二维界面处高密度激子质量的相干运动”发光杂志。

Y. Shirasaka, H. Mino, T. Kawai, I. Akai, T. Karasawa: "Spatial Behavior of Exciton-Polariton Masses in a Layered Crystal BiL_3"International Journal of Modern Physics B. 15. 3960-3964 (2001)

Y. Shirasaka、H. Mino、T. Kawai、I. Akai、T. Karasawa：“层状晶体 BiL_3 中激子-极化子质量的空间行为”国际现代物理学杂志 B. 15. 3960-3964 (2001)