High Luminosity and Dynamics on High Density electronic Excited States in Nano-Structure Materials

(1)半导体量子线中的高密度激子在高密度光激发下，在AlGaAs量子线中发现了高密度激子之间的排斥性相互作用导致的高能位移。(2)自然形成的准二维纳米结构中的高密度激子研究了层状半导体中高密度激子反冲发光的时间和空间动力学。激子带内的热分布和激子极化子群速度随带形的变化决定了高密度激子的时空动力学。(3)嵌入基体的半导体微晶中的高密度激子嵌入多孔CAPRON聚合物中的HgI_2微晶，在极低密度激发下可观察到双激子和激子非弹性发光带共存。这些非线性发光的低密度阈值是通过从基质到微晶的高效能量传递来实现的。(4)高发光有机材料中的光激发态通过光量热光谱法，直接研究了高发光材料Alq_3的非辐射弛豫。结果表明，Alq_3具有较高的发光量子产率，达到70%以上。(5)高发光π共轭聚合物聚噻吩的光激发态分散在惰性聚合物中，研究了聚噻吩中发光态的形态依赖性。发现晶格弛豫和非辐射链间相互作用的程度严重依赖于形貌。(6)在具有π共轭外周的光捕获树突子树突子中实现了光激发态，实现了光能的高效转换。研究发现，快速的能量转移和短程相互作用在小的树状大分子中起着重要的作用。

(1)High Density Excitons in Semiconductor Quantum WiresHigh energy shifts due to repulsive interactions among high density excitons were found out in AlGaAs quantum wires under high density photo-excitation.(2)High Density Excitons in Naturally Formed Quasi-Two Dimensional Nano-StructuresTemporal and spatial dynamics on recoil luminescence of high-density excitons in layered semiconductors were investigated. Thermal distribution in the exciton band and a variation of the group velocity of the exciton-polaritons depending on the band shape governs the temporal and spatial dynamics of the high density excitons.(3)High Density Excitons in Semiconductor Microcrystallites Embedded in MatricesOn HgI_2 microcrystallites embedded in porous CAPRON polymers, a co-existence of the bi-exciton and excitonic inelastic luminescence bands was observed under extremely low-density excitation. The low-density threshold of these nonlinear luminescence was realized by a high efficient energy transfer from matrices into microcrystallites.(4)Photo-Excited States in High Luminous Organic MaterialsBy a photocalorimetric spectroscopy, nonradiative relaxations in high luminous material Alq_3 were directly studied. It was found that the Alq_3 has a high luminous quantum yield more than 70%.(5)Photo-Excited States in High Luminous π-Conjugating PolymersOn polythiophene dispersed in inert polymers, morphology dependence of the luminescent states in polythiophene was investigated. It was found that a degree of the lattice relaxation and a nonradiative inter-chain interactions were seriously depending on the morphology.(6)Photo-Excited States in Light-Harvesting DendrimersOn dendrimers having π-conjugating peripheries, high efficient light energy conversion was realized. It found that rapid energy transfers occurs and short range interactions play an important role in small dendrimers.