Time-resolved near-field spectroscopic study on photophysical processes at solid/liquid interface

固/液界面光物理过程的时间分辨近场光谱研究

• 批准号: 16072217
• 负责人: TAMAI Naoto
• 金额: $ 16.83万
• 依托单位: Kwansei Gakuin University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research on Priority Areas
• 财政年份: 2004
• 资助国家: 日本
• 起止时间: 2004 至 2006
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-16072217/
• 关键词: Transient Absorption Microspectroscopy; Semiconductor Quantum Dot; Scanning Probe Microscopy; Silver Nanorod; Photoinc Crystal Fiber; Single Particle Spectroscopy; CdTe; フェムト秒; 量子ドット; 2光子励起; レーザー捕捉; 固液界面; フェムト秒顕微過渡吸収分光; ナノ微粒子; ホット電子

1) Spectroscopic Properties of Semiconductor Nanostructures by Scanning Probe Microspectroscopy Non-linear optical properties such as two-photon absorption cross section and nonlinear refractive index of CdTe QDs were found to strongly depend on a size of QDs. The figure of merit was also found to increase with decreasing the size. The size dependence of nonlinear optical properties was analyzed by the theory derived by Sheik Bahae. CdTe nanowires synthesized from QDs was analyzed by time-resolved SPM, suggesting the heterogeneity of nanowires. In addition, the exciton annihilation of nanowires increased as compared with QDs because of the energy diffusion in nanowires. In previous experiments, blinking behavior was observed for single QD embedded by PVA and trehalose. We have found that the silica coating of a single CdTe QD dramatically suppress the blinking, suggesting that the environmental condition plays an important role for luminescence properties of single QD. Furthermore, CdS … More e nanorods and QDs were synthesized at low temperature and their physicochemical properties have been examined by SPM.2) Synthesis and Characterization of Ag Nanorods Silver nanorods were prepared by a seed-mediated growth approach with chemical reduction of Ag^+ in a detergent aqueous solution. Longitudinal and transverse modes of plasmon absorption have been clearly observed in this synthetic approach. Transient absorption dynamics indicates that the coherent acoustic vibration with oscillation period of 20 to 40 ps was originated from the heat release of nanorods that induces a periodic shift of plasmon absorption bands. By the analysis of acoustic vibration, the size of synthetic nanorods and the aspect ratio have been estimated.3) Highly-sensitive, Broadband Transient Absorption Microspectroscopy Detection wavelength region was expanded up to 1.6 μm by using InGaAs photodiode as a detector, which enables us to examine the dynamics of exciton delocalization or weak intermolecular interaction dynamics in small domains at interface with high sensitivity of △OD = 10^<-7> 〜 10^<-8>..Global-pump and local-probe geometry was also successful for transient absorption SNOM experiments. Less

研究发现，CdTe量子点的双光子吸收截面和非线性折射率等非线性光学性质与量子点的尺寸密切相关。研究还发现，随着尺寸的减小，优点的数值也会增加。利用Sheik Bahae的理论分析了非线性光学性质的尺寸依赖性。利用时间分辨SPM对量子点合成的CdTe纳米线进行了分析，表明纳米线具有非均匀性。此外，由于纳米线中的能量扩散，纳米线的激子湮灭比量子点增加。在之前的实验中，我们观察到了PVA和海藻糖包埋的单个量子点的眨眼行为。我们发现单个CdTe量子点的二氧化硅涂层显著地抑制了闪烁，这表明环境条件对单个量子点的发光性能起着重要作用。此外，还在低温下合成了CdS、More e纳米棒和量子点，并用spm测试了它们的物理化学性质。2)银纳米棒的合成和表征银纳米棒采用种子介导生长的方法，在洗涤剂水溶液中化学还原Ag^+制备银纳米棒。在这种合成方法中，已经清楚地观察到等离子体吸收的纵向和横向模式。瞬态吸收动力学表明，振荡周期为20 ~ 40ps的相干声振动是由纳米棒的放热引起的等离子体吸收带的周期性位移引起的。通过声振动分析，估计了合成纳米棒的尺寸和长径比。3)采用InGaAs光电二极管作为探测器，将高灵敏度的宽带瞬态吸收光谱检测波长区域扩展到1.6 μm，使我们能够在界面小范围内检测激子离域动力学或弱分子间相互作用动力学，灵敏度为△OD = 10^<-7> ~ 10^<-8>。全局泵浦和局部探针几何结构在瞬态吸收SNOM实验中也取得了成功。少

项目成果

Transient Behavior of 2-(2',4'-dinitrobenzyl)pyridine Photochromism Studied by Ultrafast Laser Spectroscopy

超快激光光谱研究2-(2,4-二硝基苯甲基)吡啶光致变色的瞬态行为

• 发表时间: 2004
• 期刊: Chemical Physics 306
• 作者: S.Mitra;H.Ito;N.Tamai
• 通讯作者: N.Tamai

Detection of optical trapping of CdTe quantum dots by two-photon-induced luminescence

• DOI: 10.1103/physrevb.75.161305
• 发表时间: 2007-04-01
• 期刊: PHYSICAL REVIEW B
• 影响因子: 3.7
• 作者: Pan, Lingyun;Ishikawa, Atsushi;Tamai, Naoto
• 通讯作者: Tamai, Naoto

役に立つ化学シリーズ 2. 分子の物理化学

实用化学系列2.分子物理化学

• 发表时间: 2006
• 作者: 安保正一;川崎昌博編;玉井尚登(分担);川崎昌博 編
• 通讯作者: 川崎昌博 編

UV-Vis, NMR, and time-resolved spectroscopy analysis of photoisomerization behavior of three- and six-azobenzene-bound tris(bipyridine)cobalt complexes.

• DOI: 10.1021/ic0513538
• 发表时间: 2005-10
• 期刊: Inorganic chemistry
• 影响因子: 4.6
• 作者: Kyoko Yamaguchi;S. Kume;K. Namiki;Masaki Murata;N. Tamai;H. Nishihara

Molecular Translational Diffusion in Solution under Radiation Pressure of Near Infrared Laser Light

近红外激光辐射压力下溶液中的分子平移扩散

• 发表时间: 2006
• 期刊: Proceedings of SPIE 6326
• 作者: Syoji Ito;Takashi Sugiyama;Naoki Toitani;Genki Katayama;Lingyun Pan;Naoto Tamai;Hiroshi Miyasaka
• 通讯作者: Hiroshi Miyasaka