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Fabrication of functional materials into mesoscopic structures using quantum beams and application of those structures to optical devices with ultra-fast response

使用量子束将功能材料制造成介观结构，并将这些结构应用于具有超快响应的光学器件

基本信息

批准号：
09480096
负责人：
ISHIGURE Kenkichi
金额：
$ 8.51万
依托单位：
The University of Tokyo
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
1997
资助国家：
日本
起止时间：
1997 至 1999
项目状态：
已结题

项目摘要

* "RBS analysis of Langmuir-Blodgett films bearing quantum-sized CdS particles"Rutherford backscattering spectrometry is applied to an analysis of the structure of Langmuir-Blodgett (LB) films bearing quantum-sized cadmium sulfide particles (Q-CdS). Cadmium arachidate LB films before and after exposure to hydrogen sulfide are analyzed using a beam of 2 MeV ィイD14ィエD1HeィイD12+ィエD1. The change in the Cd-edge is ascribed to the Cd migration toward the substrate, which suggests that a well-ordered layer structure of the original film is disordered during Q-CdS formation. This finding indicates that the Q-CdS produced in hydrophilic interlayers cannot be two-dimensional platelets but are spherical particles.* "Changes in the surface electronic states of quantum-sized semiconductor particles induced by high energy proton irradiation"We performed steady-state and time-resolved measurements of the ion-induced emissions and photoluminescence (PL) measurement on quantum-sized semiconductor particl … More es prepared in Langmuir-Blodgett films. The proton irradiation caused a decrease in intensity of the emission via trapping sites, removing almost all the traps in the band gap. The low energy emissions, which showed a multiexponential decay, are considered to originate from a recombination of donor-acceptor pairs localizing in the surface region. Furthermore, PL spectra obtained after the irradiation changed drastically in the course of photo-oxidation of the particles.* "DFWM study of thin films containing surface-modified CdS nanoparticles"Degenerate four-wave mixing (DFWM) was used as a technique to estimate the third-order optical susceptibility, χィイD1(3)ィエD1(-ω ; ω, -ω, ω), of thin films prepared from cadmium sulfide (CdS) colloidal solutions. The formation of CdS films on a substrate, without any change in the particle size, enhanced the quantum yield of an excitonic band by removing a large number of surface traps. This film showed a large χィイD1(3)ィエD1 value near 〜 10ィイD1-7ィエD1 esu around the exciton resonance at room temperature. This was possibly brought about by an effective surface passivation as well as a high CdS microcrystallite concentration.* "Resonant third-order optical nonlinearity in the layered perovskite-type material (CィイD26ィエD2HィイD213ィエD2NHィイD23ィエD2)ィイD22ィエD2PbIィイD24ィエD2"The third-order nonlinear optical susceptibility, χィイD1(3)ィエD1(-ω ; ω, -ω, ω), of the layered perovskite-type material (CィイD26ィエD2HィイD213ィエD2NHィイD23ィエD2)ィイD22ィエD2PbIィイD24ィエD2 is measured by a transient four-wave mixing (FWM) technique using a 200-fs-pulse laser source. The maximum |χィイD1(3)ィエD1| value is 1.6 × 10ィイD1-6ィエD1 esu at the lowest-exciton resonance at 8 K. Longitudinal and transverse relaxation times of the excitons are 7 ps and 0.2 ps ; respectively. For excitation below the exciton resonance, biexciton contribution to the FWM signals was observed. The dephasing energy of the biexcitons was estimated to be larger than 10 meV. Less

*“承载量子尺寸CdS颗粒的Langmuir-Blodgett薄膜的RBS分析”卢瑟福后向散射光谱法应用于承载量子尺寸硫化镉颗粒（Q-CdS）的Langmuir-Blodgett （LB）薄膜的结构分析。用2 MeV的γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ。Cd边缘的变化归因于Cd向衬底的迁移，这表明在Q-CdS形成过程中，原始薄膜的有序层结构被打乱了。这一发现表明亲水中间层中产生的Q-CdS不可能是二维血小板，而是球形颗粒。*“高能质子辐照诱导的量子尺寸半导体粒子表面电子态的变化”我们对量子尺寸半导体粒子的离子诱导发射和光致发光（PL）进行了稳态和时间分辨测量。质子辐照使捕获点的发射强度降低，几乎消除了带隙中所有的捕获点。低能辐射表现出多指数衰减，被认为是由在表面区域的供体-受体对的重组引起的。此外，辐照后得到的PL光谱在粒子的光氧化过程中发生了很大的变化。*“含有表面修饰的CdS纳米粒子薄膜的DFWM研究”采用简并四波混合（DFWM）技术来估计硫化镉（CdS）胶体溶液制备的薄膜的三阶光学磁化率χ γ γ D1(3) γ γ γ D1（-ω; ω, -ω, ω）。在衬底上形成CdS薄膜，而颗粒大小没有任何变化，通过去除大量的表面陷阱，提高了激子能带的量子产率。该薄膜在室温下激子共振周围有较大的χ γ γ γ D1(3) γ γ γ D1值，在~ 10 γ γ D1 ~ 7 γ γ γ D1附近。这可能是由于有效的表面钝化和高镉微晶浓度所致。*“分层perovskite-type共振三阶光学非线性材料(CィイD26ィエD2HィイD213ィエD2NHィイc15ィエD2)ィイD22摊位ィエD2PbIィイD24ィエD2”三阶非线性光学易感性,χィイD1(3)ィエD1(-ω-ω;ω,ω),分层perovskite-type材料(CィイD26ィエD2HィイD213ィエD2NHィイc15ィエD2)ィイD22摊位ィエD2PbIィイD24ィエD2由瞬态四波混频测量(光)技术使用200 - fs -脉冲激光源。在最低激子共振温度为8 K时，|的最大值为1.6 × 10 γ γ γ -6 γ γ γ γ。激子的纵向弛豫时间为7 ps，横向弛豫时间为0.2 ps；分别。对于激子共振以下的激励，观察到双激子对FWM信号的贡献。估计双激子的消相能量大于10 meV。少