Cavity ring-down spectroscopy on size-selected, supported clusters

对尺寸选定的支撑团簇进行腔衰荡光谱

• 批准号: 5404784
• 负责人: Professor Dr. Ulrich Heiz
• 金额: --
• 依托单位: Lehrstuhl für Physikalische Chemie
• 依托单位国家: 德国
• 项目类别: Priority Programmes
• 财政年份: 2003
• 资助国家: 德国
• 起止时间: 2002-12-31 至 2009-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/5404784?language=en
• 关键词: Cavity; ring; down; spectroscopy; size

This project aims at the spectroscopic study of size-selected, supported clusters in the photon energy range from 1.7 eV to 6.0 eV by means of the evanescent wave cavity ring-down spectroscopy in order to study the electronic structure and optical properties of size-selected metal and semiconductor clusters supported on oxide surfaces. Oxides are ideal support materials as important optical transitions of clusters lie energetically within their band gaps. For these studies the EW-CRDS, an ultrasensitive surface spectroscopy, will be developed and optimized for studying size-selected, supported clusters under UHV conditions and at cryogenic temperatures. Two experimental schemes will be considered: a) monolithic folded resonators and b) miniature cubical optical resonators. In both cases the clusters will be deposited onto the planes of total internal reflection of the two optical devices and will be probed spectroscopically by CRD through adsorption of the associated evanescent waves. Both cavities have a polarization-independent finesse, allowing polarization-dependent phenomena to be studied. This experimental scheme will be used in the first term of this program to study optical absorptions of deposited, metal clusters of a single size in order to investigate differences in the electronic structure of these coinage metal clusters and to obtain information of their morphology and structure by analyzing polarization-dependent absorptions. The clusters will either be deposited directly onto the SiO2 surface of the optical devices or onto thin MgO and TiO2 films grown onto the amorphous silica surface of the resonators.

本项目的目的是通过倏逝波腔衰荡光谱法，在光子能量范围从1.7 eV到6.0 eV内，对尺寸选定的支撑团簇进行光谱研究，以便研究氧化物表面上支撑的尺寸选定的金属和半导体团簇的电子结构和光学性质。氧化物是理想的支撑材料，因为团簇的重要光学跃迁能量位于它们的带隙内。对于这些研究的EW-CRDS，一个超灵敏的表面光谱，将开发和优化研究尺寸选择，支持集群在超高真空条件下，在低温下。将考虑两种实验方案：a）单片折叠谐振腔和B）微型立方体光学谐振腔。在这两种情况下，团簇将沉积在两个光学器件的全内反射平面上，并通过吸收相关的倏逝波由CRD进行光谱探测。这两种腔都具有与偏振无关的精细度，可以研究偏振相关的现象。这个实验方案将用于本计划的第一学期研究沉积的单一尺寸的金属团簇的光学散射，以研究这些钴金属团簇的电子结构的差异，并通过分析偏振相关的散射来获得它们的形态和结构的信息。团簇将直接沉积在光学器件的SiO2表面上，或者沉积在谐振器的无定形二氧化硅表面上生长的薄MgO和TiO 2膜上。