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

(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_1-x&gt；As/AlAs半导体量子线中激子光致发光的多体效应及其动力学。阐明了量子波间激子的累积动力学对多体效应的动力学起着重要的作用。因此，高密度激子的相空间填充效应导致了高密度激发下发光的蓝移。另一方面，观察到激子沿QWR的不对称扩散。在高密度激发下，激子扩散的增强被揭示出来。(2)用空间分辨简并四波混频技术研究了层状半导体纳米界面激子的多体效应和激子动力学。因此，它有了b…进一步阐明了在保持量子相干性的情况下，激子的量子态在宏观上传播。激子量子态的空间传播动力学可以用包含弱相互排斥激子相互作用的Gross-Pitaevskii方程来解释。(3)在聚合物和玻璃中生长出CuL、HgI_2、PbI_2和TII微晶。研究了微晶中激子的各种体效应和激子-晶格相互作用。在CuL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。在这些激子系统中，观察到了双激子的非线性发光和激子的非弹性散射。随着晶体尺寸、温度和激发密度的改变，多体效应的机理发生了变化。另一方面，在TiI、HgI_2和PbI_2微晶上，微晶与基质之间的相互作用增强了激子-晶格相互作用。在TiI和HgI_2的情况下，从基质到微晶的有效能量传递控制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Alq3和六核6-甲基吡啶硫代铜(I)的光激发态的动力学。在Alq3上，我们提出了一个新的光激发态模型，该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。较少

(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