Surface enhance Raman scattering in aligned metal/semiconductor nanocrystals

对齐金属/半导体纳米晶体中的表面增强拉曼散射

基本信息

批准号：
18540319
负责人：
YAMAMOTO Aishi
金额：
$ 2.51万
依托单位：
Nara Institute of Science and Technology
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2006
资助国家：
日本
起止时间：
2006 至 2007
项目状态：
已结题

项目摘要

We studied electronic interaction between semiconductor nanocrystals and metal nanocrystals by measuring Raman scattering and photoluminescence spectra. First, we discussed Raman scattering spectral shape of semiconductor nanocrystals. The Raman scattering spectral shape was calculated by a phonon confinement model considering the relaxation of the momentum conservation rule. The semiconductor nanocrystals we used had a possibility to farm zincblende or wurtzite crystal structure. The calculated Raman scattering spectra assuming wurtzite structure were more preferable to explain the experimental spectra. This result was consistent with the crystal structure obtained from TEM images. Our finding indicates that we can determine the nanocrystal structure from the Raman scattering analyses without using e. g. TEM.Next, we fabricated close-packed semiconductor/metal mixed nanoparticle monolayers and measured the Raman scattering and photoluminescence spectra simultaneously, in order to inve … More stigate the influence of the Raman scattering and photoluminescence properties of semiconductor nanoparticles on the surface plasmons of metal nanoparticles. The TEM images showed that close-packed semiconductor/metal nanoparticle monolayers were successfully fabricated. With an increase of the metal nanoparticle ratio, the PL intensity decreased dramatically, while the Raman scattering intensity increased slightly. The time-resolved photoluminescence spectra showed that the photo-excited exciton energy in semiconductor nanocrystals transferred to metal nanoparticles. The observed semiconductor-nanoparticle number density dependences of the Raman scattering and photoluminescence intensities were able to be explained by an energy transfer model which considered the effects of electromagnetic enhancement and energy transfer. We demonstrated that conducting simultaneous measurements of Raman scattering and photoluminescence spectra is a useful technique to understand the interaction between metal and semiconductor nanostructures. Less

我们通过测量拉曼散射和光致光谱研究了半导体纳米晶与金属纳米晶之间的电子相互作用。首先，我们讨论了半导体纳米晶体的拉曼散射光谱形状。考虑到动量保护规则的松弛，通过声子限制模型计算了拉曼散射光谱。我们使用的半导体纳米晶体有可能耕种锌蓝色或葡萄球菌晶体结构。假设Deadzite结构更喜欢解释实验光谱的计算出的拉曼散射光谱。该结果与从TEM图像获得的晶体结构一致。我们的发现表明，我们可以通过不使用e来确定拉曼散射分析的纳米晶体结构。 g。 tem.next，我们制造了封闭的半导体/金属混合纳米颗粒单层，并简单地测量了拉曼散射和光致发光光谱，以便进一步……更多地阐明了拉曼散射和光致发光的影响，而光散射的影响是金属纳米属物质表面血浆中半纳米粒子的含量。 TEM图像显示，已成功制造了近距离包装的半导体/金属纳米粒子单层。随着金属纳米颗粒比的增加，PL强度急剧下降，而拉曼散射强度略有增加。时间分辨的光致发光光谱表明，光激发的刺激能量在半导体纳米晶体中转移到金属纳米颗粒上。观察到的半导体 - 纳米颗粒数密度依赖性的拉曼散射和光致发光强度的依赖性能够通过能量转移模型来解释，该模型考虑了电磁增强和能量传递的影响。我们证明，对拉曼散射和光效率光谱进行同时测量是一种有用的技术，可以理解金属和半导体纳米结构之间的相互作用。较少的